Merge pull request #739 from gradha/pr_adds_to_quit_docs

Adds to quit docs

doc/manual.txt

@@ -4708,7 +4708,11 @@ fatal pragma
 ------------
 The `fatal`:idx: pragma is used to make the compiler output an error message
 with the given content. In contrast to the ``error`` pragma, compilation
-is guaranteed to be aborted by this pragma.
+is guaranteed to be aborted by this pragma. Example:
+
+.. code-block:: nimrod
+  when not defined(objc):
+    {.fatal: "Compile this program with the objc command!".}
 
 warning pragma
 --------------

lib/system.nim

@@ -923,6 +923,10 @@ proc quit*(errorcode: int = QuitSuccess) {.
   ## The proc ``quit(QuitSuccess)`` is called implicitly when your nimrod
   ## program finishes without incident. A raised unhandled exception is
   ## equivalent to calling ``quit(QuitFailure)``.
+  ##
+  ## Note that this is a *runtime* call and using ``quit`` inside a macro won't
+  ## have any compile time effect. If you need to stop the compiler inside a
+  ## macro, use the ``error`` or ``fatal`` pragmas.
 
 template sysAssert(cond: bool, msg: string) =
   when defined(useSysAssert):