- Failing on splay test, narrowed down to probable GC bug
- propCache of ObjShape object corrupted after second GC

Added regression test, see:
./higgs --nostdlib splay-fail.js
- Fixed bug with splay benchmark
- Bug caused by temporary JS string data leaking into ObjShape
  propCache and later being corrupted during GC
- Fixed parser bug wrt global function expressions
- Added regression test
Merge branch 'master' of github.com:maximecb/Higgs into dev-maxime

Conflicts:
	source/parser/parser.d
- Minor optimization wrt numberToString
- Updated benchmark.py to support V8
- Added microbenchmark
- Added notes
- Minor optimization to global calls
- Small optimization, biasing register allocation for return values
- Optimized addIntFloat to allow register reusing on add
- Optimized array property access