Update strings.js

update new strings
Cleaned up the preferences ids
Fixed forgotten id
Added Localisation for the Loading... message
Cleaned up whitespace and indents
Rewrite _adjustFontSize() so it can adjust font size by more than a single pixel at a time
Add in persistence of font size between Brackets sessions
Limit the maximum negative value of fontSizeAdjustment so the fonts don't get too small
Persisted font sizes now load on currentDocumentChange event
Disable Font Size commands when there is no current document
Update UI appropriately when the application first starts and when the current document changes
Small comment change
Small comment change (again)
Added preferences migration code
Exported handleClientIdChange
Small comment change (Part III)
add missing comma
Final migration handling implemented
Reverted change in PreferencesManager
Merge remote-tracking branch 'upstream/master' into persist_font_size