[CB-4222] Update Upgrading Guide for 2.9.0 -> 3.0.0 for iOS
Removed directions about `chown` w.r.t. CLI use: unnecessary anymore.
Added plugin specification.
added corePluginInstall guide
[CB-4031] [BlackBerry10] Fixes for BB10 platform guide

- fixed spacing issues
- updated invalid commands
- removed merge conflict artifacts
- added instructions to add ndk tools to path
[CB-4222] (Updated) - Update Upgrading Guide for 2.9.0 -> 3.0.0 for iOS
[CB-3962] cleaned up plugin spec, conforming to editorial guidelines
[CB-3816] shrink overly wide screen shots
[CB-3816] add plugin doc to CLI, adapted from new plugman doc
[CB-3816] added simple use case for removing a plugin
[CB-3816] modify plugman doc to remove & xref CLI plugin doc; basic cleanup
[CB-3816] xref to plugman doc; page to serve as model for upgrading guides for 3.0
[CB-3827] swap guide & ref content in home page; rm outdate CL section; minor chuffling & cleanup
[CB-3827] redirect hidden xrefs to renamed app dev guide, still to come
[CB-3827] Superficial markdown convention to make it easier to grep heading structure
[CB-3827] added platform-specific links to top of each Platform Guide to help w/context; standardized license header; at least 1 file got re-coded
[CB-3827] Project Settings => Configuration Reference
[CB-3827] Extended Hybrid Applications => Hybrid Application Guide
[CB-3827] promote CLI content on home page over Platform Guides
[CB-3962] specify various editorial conventions