Fix #600, 601

[eb1]

Fixes #600, #601 .

Changes proposed in this request:

• Gloss navigation now looks at the gloss field in each pile to find the next empty slot.
• Fixed a few issues with FT navigation. Should move to one past the current selection, and alert the user when FT is done for the chapter.
• Enable / disable the navigation buttons when the FT editor edit area is selected / blurred.
• Also bumped the version to 1.17.3 (62), and update to the latest cordova-ios (7.1.1)

@adapt-it/developers