Implemented adding categories in REST

CategoryService was refactored to make use of RemoteCategory objects.

The add category view controller no longer syncs categories after
creation since REST will already return the new category. When sync is
moved to CategoryService, we need to trigger it after creation for
XML-RPC remotes.
Refactor category creation

If the user tries to create a category with a name that already exists,
let's pretend we just created it and use the existing category instead
of failing.
Moved category syncing to CategoryService

Implemented REST category sync
Force blog sync on blog details view
Sync categories after creation for XML-RPC
Merge branch 'develop' into issue/2551-category-service
CHange assert to check for empty strings besides nil
One class per line
Removed unnecessary check
Merge branch 'develop' into issue/2551-category-service
Updates font and color for UISearchBar.
Fixes an issue where trailing italics could be cropped.

Work around for an issue in DTCoreText.
Style tweaks.
Update cocoa pods version.
Update crashlytics version.
Disable taplytics on debug builds

When you set up exception breakpoints, Taplytics hits them twice on
launch

refs #2437
Merge pull request #2570 from wordpress-mobile/issue/2551-category-service

#2551 REST Cleanup: Categories
Merge pull request #2612 from wordpress-mobile/issues/2224-fix-italic-frame

Fixes an issue where trailing italics could be cropped.
Merge pull request #2628 from wordpress-mobile/issue/2437-disable-taplyics-on-debug

Disable taplytics on debug builds
Explicitly setting the SettingsVC tableView rowHeight to avoid the rowHeight changing unexpectedly during transition to the AboutVC