Promote "echo" syntax without parenthesis

doc/manual/exceptions.txt

@@ -15,15 +15,15 @@ Example:
     try:
       var a = readLine(f)
       var b = readLine(f)
-      echo("sum: " & $(parseInt(a) + parseInt(b)))
+      echo "sum: " & $(parseInt(a + parseInt(b)))
     except OverflowError:
-      echo("overflow!")
+      echo "overflow!"
     except ValueError:
-      echo("could not convert string to integer")
+      echo "could not convert string to integer"
     except IOError:
-      echo("IO error!")
+      echo "IO error!"
     except:
-      echo("Unknown exception!")
+      echo "Unknown exception!"
     finally:
       close(f)
 

doc/manual/modules.txt

@@ -144,7 +144,7 @@ modules don't need to import a module's dependencies:
 
   # B.MyObject has been imported implicitly here:
   var x: MyObject
-  echo($x)
+  echo $x
 
 Note on paths
 -----------

doc/manual/procs.txt

@@ -129,9 +129,9 @@ to supply any type of first argument for procedures:
 
 .. code-block:: nim
 
-  echo("abc".len) # is the same as echo(len("abc"))
-  echo("abc".toUpper())
-  echo({'a', 'b', 'c'}.card)
+  echo "abc".len # is the same as echo len "abc"
+  echo "abc".toUpper()
+  echo {'a', 'b', 'c'}.card
   stdout.writeLine("Hallo") # the same as writeLine(stdout, "Hallo")
 
 Another way to look at the method call syntax is that it provides the missing
@@ -486,7 +486,7 @@ state are automatically saved between calls. Example:
       inc(i)
 
   for ch in items("hello world"): # `ch` is an iteration variable
-    echo(ch)
+    echo ch
 
 The compiler generates code as if the programmer would have written this:
 
@@ -494,7 +494,7 @@ The compiler generates code as if the programmer would have written this:
   var i = 0
   while i < len(a):
     var ch = a[i]
-    echo(ch)
+    echo ch
     inc(i)
 
 If the iterator yields a tuple, there can be as many iteration variables

doc/manual/stmts.txt

@@ -234,11 +234,11 @@ Example:
   var name = readLine(stdin)
 
   if name == "Andreas":
-    echo("What a nice name!")
+    echo "What a nice name!"
   elif name == "":
-    echo("Don't you have a name?")
+    echo "Don't you have a name?"
   else:
-    echo("Boring name...")
+    echo "Boring name..."
 
 The ``if`` statement is a simple way to make a branch in the control flow:
 The expression after the keyword ``if`` is evaluated, if it is true
@@ -269,17 +269,17 @@ Example:
 
   case readline(stdin)
   of "delete-everything", "restart-computer":
-    echo("permission denied")
-  of "go-for-a-walk":     echo("please yourself")
-  else:                   echo("unknown command")
+    echo "permission denied"
+  of "go-for-a-walk":     echo "please yourself"
+  else:                   echo "unknown command"
 
   # indentation of the branches is also allowed; and so is an optional colon
   # after the selecting expression:
   case readline(stdin):
     of "delete-everything", "restart-computer":
-      echo("permission denied")
-    of "go-for-a-walk":     echo("please yourself")
-    else:                   echo("unknown command")
+      echo "permission denied"
+    of "go-for-a-walk":     echo "please yourself"
+    else:                   echo "unknown command"
 
 
 The ``case`` statement is similar to the if statement, but it represents
@@ -326,13 +326,13 @@ Example:
 .. code-block:: nim
 
   when sizeof(int) == 2:
-    echo("running on a 16 bit system!")
+    echo "running on a 16 bit system!"
   elif sizeof(int) == 4:
-    echo("running on a 32 bit system!")
+    echo "running on a 32 bit system!"
   elif sizeof(int) == 8:
-    echo("running on a 64 bit system!")
+    echo "running on a 64 bit system!"
   else:
-    echo("cannot happen!")
+    echo "cannot happen!"
 
 The ``when`` statement is almost identical to the ``if`` statement with some
 exceptions:
@@ -435,7 +435,7 @@ Example:
         if a[j][i] == 7:
           found = true
           break myblock # leave the block, in this case both for-loops
-  echo(found)
+  echo found
 
 The block statement is a means to group statements to a (named) ``block``.
 Inside the block, the ``break`` statement is allowed to leave the block
@@ -462,10 +462,10 @@ While statement
 Example:
 
 .. code-block:: nim
-  echo("Please tell me your password: \n")
+  echo "Please tell me your password: \n"
   var pw = readLine(stdin)
   while pw != "12345":
-    echo("Wrong password! Next try: \n")
+    echo "Wrong password! Next try: \n"
     pw = readLine(stdin)
 
 

doc/manual/types.txt

@@ -546,7 +546,7 @@ so that the builtin ``echo`` proc does what is expected:
 .. code-block:: nim
   proc echo*(x: varargs[expr, `$`]) {...}
 
-  echo(@[1, 2, 3])
+  echo @[1, 2, 3]
   # prints "@[1, 2, 3]" and not "123"