[timob-10688] Docgen.py: adding flag to ignore external directories during output

This will be used mainly for module doc generation. Allows us to validate against the Titanium docs, but only output the module's docs
[TIMOB-10688] Docgen: adding modulehtml generator
[TIMOB-10688] Module build.py template: adding YML apidoc generation and option to skip it
Merge branch 'master' of https://github.com/appcelerator/titanium_mobile into timob-10688
[TIMOB-10688] Module build.py template: updating warning message
Merge branch 'master' of https://github.com/appcelerator/titanium_mobile into timob-10688
[TIMOB-10688] process_yaml in docgen.py now accepts a second optional argument, options
Merge pull request #4210 from jonalter/timob-10688

[TIMOB-10688]