Replace bumper with grunt-bump, closes item:519

[Usage][]:

```bash
grunt bump[:[patch|minor|major|build|git]]
```

[usage]: https://github.com/vojtajina/grunt-bump#usage-examples
Sync description with GitHub
Merge pull request #335 from tlvince/refactor/grunt-bump

Replace bumper with grunt-bump, closes item:519
Merge pull request #337 from tlvince/refactor/package-description

Sync description with GitHub, closes item:520
bowerInstall -> wiredep, closes item:522
Merge pull request #338 from tlvince/refactor/wiredep

bowerInstall -> wiredep, closes item:522
Add grunt bumpAndroid, ref item:420
Ignore build dir
Run Travis as an Android project

… though all Travis env's have `node` on `$PATH`.
Document cca plugins
Add Travis build script
Disable bumpAndroid commit for now
Copy mobile manifest on build, fixes item:521
Travis: install local npm packages

Necessary now as we're an Android project (in Travis' eyes)