Update mingw-toolchain.xml

Added "O3" define to change the compiler optimization flag
Added "no_shared_libs" define to static compile an executable that do not need mingw shared libs (libgcc, libstdc++)
Update mingw-toolchain.xml

Moved changes to link section ;)
Fixed `haxelib path ...` parsing.
Currently `haxelib path hxcpp` gives:
path/to/hxcpp/
-D hxcpp=3.1.0

Notice there is version number at the end.
Merge pull request #139 from andyli/tools-fix

Fixed `haxelib path ...` parsing.
Merge pull request #140 from andyli/travis

init AppVeyor config
Better `haxelib path ...` parsing. As suggested by Hugh in #139.
badges!

[skip ci]
Merge pull request #130 from lguzzon/patch-1

Update mingw-toolchain.xml
Test no_shared_libs flag for MINGW.  Do not use -O2 in debug mode
Disable precalculated hashes until I can work out why it fails sometimes on mac
Do not try to use precomputed hash of foreign string.  Move hash code to cpp to allow easier debug.
Added HXCPP_PARANOID define for extra integrity checks.
Look for local .haxelib directory
[AppVeyor] shadow clone for speed