CB-6491 add CONTRIBUTING.md
[Windows8] re-added BOM : CB-5421 Add BOM to all html, js, css files to ensure app can pass Windows Store Certification
Split out cordova-lib: move cordova-cli files

HISTORY:
git log <file> will show no history from before this commit for files that
moved. To see full history use either
git log --follow <file>
or
git log cli_pre_lib <old file name>

'cli_pre_lib' is a tag for the last commit in cordova-cli repo made before
cordova-lib was split out.
Remove all cordova-lib files
Update package.json to use cordova-lib
Fix require paths to use cordova-lib
Fix cordova-lib dep version in package.json
CB-6648 Adding a flag for experimental features
CB-6649 Removing experimental flag from positional arguments
Fixing failing CLI tests by removing 'experimental' key

Our cli tests expect that *exactly* a very strict set of options to be passed
on to handlers, instead of making sure that *at least* that set is
passed.