[MERGE #1580 @dilijev] .gitignore: add *.bak, *.orig, files generated by VS, and reorganize .gitignore file
[MERGE #1580 @dilijev] .gitignore: add *.bak, *.orig, files generated by VS, and reorganize .gitignore file

Merge pull request #1580 from dilijev:ignore

Added
*.bak
*.orig

Added many more types of files that are sometimes generated by VS.

Organized ignore filters into categories, and sorted lines within categories.

mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore