Added optimization of debug information for Mircosoft debuggers to -gc. When this optimization is enabled, '.' is replaced with '@' within type names. Also arrays passed to functions are now marked as references instead of pointers, because the pointer confuses the visual studio debugger.
Add -vgc switch

The following known allocations are intentionally not handled:

* AssertExp
* CmpExp
* AssignExp: Calls _d_arrayassign
* Hidden function errors: Are already deprecated
* SwitchErrorStatement

All these cases only allocate by throwing exceptions
and disallowing them would impact user code a lot. In
order to really solve such issues we need some way to
throw exceptions without GC-allocation.

Also not handled are indirect calls to user-defined
functions which may allocate (calling postblits in
array assignment for example). As this commit does
not provide a way to mark a function as @nogc there's
no way to know if such functions actually allocate.

These indirect calls to user defined functions must
be revisited when a @nogc attribute is introduced.
Recognize shared libraries when linking
Only collect shared libs on *nix
Proper conditial
Merge pull request #3397 from Yoplitein/master

Recognize shared libraries as valid files when linking
Fixup DDMD build due to ternary expression not implicitly converting to char*.
Merge pull request #3401 from AndrejMitrovic/Fixup3396

Fixup DDMD build due to ternary expression not implicitly converting to char*.
Don't indent location part of diagnostic messages
Merge pull request #3402 from CyberShadow/ambig-indent

Don't indent location part of diagnostic messages
Don't rebuild d_do_test.exe every time on Windows
Merge pull request #3403 from CyberShadow/d_do_test_exe

Don't rebuild d_do_test.exe every time on Windows
Merge pull request #1886 from jpf91/vgc

Implement nogc framework (warn about GC allocations)
include dependencies for all object files
Use 'if' instead of 'else if' to avoid a comment the ddmd converter can't handle
Fixed "@disable this" propagating through references (issue 8296)
Merge pull request #3409 from yebblies/elseif

[DDMD] Use 'if' instead of 'else if' to avoid a comment the ddmd converter can't handle
Visual Studio build fix (add nogc.c)
Merge pull request #3412 from CyberShadow/vs-20140330

Visual Studio build fix (add nogc.c)
fix Issue 12497 - ICE on string mixin with non-string operand