addressing mark traceur’s comments

<https://gerrit.wikimedia.org/r/#/c/59405/11/includes/Config.php>
<https://gerrit.wikimedia.org/r/#/c/59405/11/resources/js/ext.gwtoolset.js>

* added an HTML form to the save mappings dialog and removed the keyUp handler
* added comment on the keyCode within handleDialogKeyUp()
* added default text to the title and href text of createBackLink()
* added in use of jquery.spinner
* addressing jenkins issues with variable names
* altered createBackLink() so that it has a non-blank default for the anchor text and title
  and added evt.stopPropagation()
* altered html element creation from e.g. $( '<div />' ) to $( '<div>' )
* attempted to add correct grammar, full technical terms and punctuation to the i18n documentation
* changed += 1 to ++
* changed addButtons() so that it now applies itself directly to the corresponding classed elements
* changing html element creation from e.g. $( '<div />' ) to $( '<div>' )
* changed some code comments
* changing the use of .attr
  - so that when only one attribute is added, it is added directly rather than as an object
  - so that when an object is used, each entry is on a separate line
  - so that when non js reserved words are added as part of an object no quotes are used
* cleaned-up some i18n keys
* corrected grammar, added full technical terms and punctuation to the i18n documentation
* corrected spelling errors
  - url -> URL
  - inthe -> in the
* got rid of the JavaScript prompt for a metadata mapping name and replaced it with jquery.dialog
* merged complimentary changes from the php branch
* messages are now retrieved from within the calling functions rather than from a messages object
* removed jquery.ui from the extension, replaced it with resource loader’s jquery.ui modules
* removed setConsole() method and its related calls
* removed superfluous newline spotted by siebrand
* re-ordered var definintions so a list of vars has undefined vars listed first
* replaced <br /> with two new lines
* replaced [$1] with ($1)
* the $ajaxLoader is now created with $.createSpinner()

Change-Id: Ib7c74caf7a0fbfa80136b263653610fc3e2fd225