Add amalgamated build option to build scripts.
At the moment only works and tested on Linux platform.
Keep Ubuntu happy. Works and tested OK on Fedora and Ubuntu.
Keep Apple happy. Now works on Apple (Xcode and Makefile) also.
Keep Microsoft happy. Now also works on MSVC.
Revert back changes to Engine codes as they are now excluded for AMALG.
Merge branch 'amalgamated' into master.