download github source files with correct encoding

fixes #247
Use KnownAliases in order to translate more libs - references #241
Merge branch 'fix-247' of github.com:mexx/Paket

Conflicts:
	src/Paket/InstallProcess.fs
Fix merge conflict
release notes
Bump version to 0.6.7
add section about referencing branches other than master
always retrieve commit hash to allow locking of any branch