Fixed memory leak from '--watch' flag.

As I initially feared, we were actually nesting closure environments with each new `getSourceFile`.

Fixes #366.
Remove ByteOrderMark
add generateBOM switch
Add tests for generateBOM switch
make the BOM visible in the test output
Merge branch 'master' into bom

Conflicts:
	src/compiler/commandLineParser.ts
	src/compiler/emitter.ts
Addressed code review feedback.
do not reorder signatures from derived and base types
change name of the flag to emitBOM
Style and comments.
rename test
Merge pull request #367 from Microsoft/theDisintegrationOfThePersistenceOfMemory

Fixed memory leak when using '--watch' flag.
Scan octal literals
Add es5 directive on scanner es5 tests
Error on octal literals in ES5 and strict mode
Add test for octal literals in es3 strict mode
fixed build breaks in perftc
Merge branch 'master' into bom
Merge pull request #377 from Microsoft/bom

add a new compiler command line switch for generating utf-8 BOM in the output
Handle sys.exit in perftc