Charts: Concat Flot and plugins during build

Fixes gh-1276
- Cleaned up JSHint globals at top
- Removed additional flotPie depends since it is no longer a descrete
file
- Any future plugins will be included in this output file as long as
they keep the flot* naming
Merge pull request #1292 from nschonni/concat-flot-plugins-1276

Charts: Concat Flot and plugins during build