fixed duplicated tags in vim-android.txt
Merge pull request #8 from iromli/duplicate-tags

Duplicated tags in vim-android.txt
Fixes and improvements to tag generation code.

- Some source directories in gradle projects were not being added to the ctags
  command.
- Merged the AndroidUpdateAndroidTags and AndroidUpdateProjectTags into one
  single AndroidUpdateTags command.
- Added XML tag generation for resource and layout files.
- Fixed duplicate entries in the source paths.
Set the path variable with the sources paths.