[Web] Core refactoring

[jahorton]

Part of our targeted goals for KMW 10.0:

• Rework the KeymanWeb (case-sensitive) global variable.
  • We need to preserve it for compatibility with the existing keyboard interface API; said API should become the only accessible functionality through this object.
  • Will need to check the results' compatibility with the CJK (pick-list) and EuroLatin 2 keyboards.
• The core keymanweb object should contain wrapper functions to the API with higher-quality names.
  • E.g, KeymanWeb.KI() should be wrapped by keyman.submodule.index().
  • The appropriate submodule's name is yet TBD.
• Our original top-level namespace-like structure is no longer appropriately named.
  • Change the tavultesoft.keymanweb object to simply keyman.

The above points are all addressed by #356.

Side-effects:

• The following projects will need individualized adjustments to match the new structure:
  • Keyman Developer (Addressed by KMW namespace change - Developer fix #386)
  • Keyman for Android (Addressed by Modified the KMEA keyboard.html to use the new keyman JS namespace #392)
  • Keyman for iPhone and iPad (Addressed by [iOS] KMW core refactoring #391)
  • keymanweb.com (Addressed by https://github.com/sillsdev/keyman-keymanweb.com/pull/23.)
  • The Bookmarklet feature (Addressed by https://github.com/sillsdev/keyman-r.keymanweb.com/pull/17.)
  • Correlated changes may be needed on our other sites - investigate and fix.
    • We have an intro-ish section on keyman.com at https://keyman.com/developer/keymanweb/ that will need adjustment when the feature reaches stable. There's only one version of the page, though, so... a decision needs to be made on how to handle this.
    • Moved to https://github.com/sillsdev/keyman-keyman.com/issues/53.
• help.keyman.com's KMW 10.0 reference section - update to detail the new API referencing structure!
  • Addressed by https://github.com/sillsdev/keyman-help.keyman.com/pull/114.

[jahorton]

All staging work has been merged, and the last remaining point (for the keyman.com website) has been moved to sillsdev/keyman-keyman.com#53.