squashed commits, implemented a new Metadata Editor window
Second round of code change, fixes and more!

changed some comments in the code

hidden tab is implemented, however it is very very messy!  I've commented below in parts of interest.

cleaned up code, hiding/unhiding fully implemented

finalized changes, removed uneeded code, awaiting inspection

fixed typo is variable name

fixed accidental code removal from trackEditor.xul

"added a newline at the end of the trackEditor.xul file"

"added a correct version of the trackEditor.xul with the proper code
modification"

more indentation fixes ... :\

clearly need more sleep, yet again
Merge branch 'enhancedMetadataEditorV2' of https://github.com/luisgmarine/nightingale-hacking into enhancedMetadataEditorV2