Add filter preview images
Filter classes made for each new filter
Add methods to filters to get filter name and filter image
Removed filter application through AdCreationManager and changed it to be done in the filter activity

The enum thing for filters gets messy when there are lots of them, and
it is unnecessary now that we have a better filter system set up.
Adjusted default settings of filters to be in line with regular use.
Changed size of images in scroll view
enlarge images in browse activity
Small fixes and comments added
center images in grid, make single column
Merge pull request #143 from elihart/moreFilters

More filters
fetching relevant data and presenting it, need to work on layout
improve layout
Added text labels to filter scroller
Merge branch 'master' of https://github.com/maplesyrup/maple-android into moreFilters
make image appear in full screen activity on click
full screen works
clean code and add comments
Changed color adjustment to use the filter library

Much cleaner then implementing it ourselves like before. Also changed
the settings to be brightness and contrast (instead of gamma).

Also fixed filters that weren't working
change fill_parent (deprecated) to match_parent
Merge remote-tracking branch 'upstream/master' into improveMain