Merge pull request #26 from oleholstandersen/master

Preparing for multiple developers
Removed unused spellcheck stuff
Added skeleton insert heading operation and author listener remove nav points when headings are removed
Added AuthorOperation to insert headings at same or at sub-level, also added ncx framework based on the standard , but with auto-id generation
Added shortcut keys to heading actions
Focus is now returned to document frame after inserting heading
Added Missing jar libs
A bit of cleanup of insert heading operation
Added half finished ncx generation method to EpubUtils (not sure if it is usefull)
Added sample epub
Commented out un-finished ncx generation code
Merge pull request #27 from oleholstandersen/nota-783

Nota 783
Added skeleton RemoveHeadingOperation
Implementing nav file updator
Added UpdateNavigationDocumentsOperation and a single unit test
Finished first sort-of-working version of the three operations: Insert/Remove/Update nav
Fixed getCurrentElement, selection efter insert and remove ops and added a bit of css
Moved image dimension function from operation to utils class
Merge pull request #28 from oleholstandersen/nota-783

Nota 783
nota-782 almost fixed