Deprecate FCKeditor

(from [95c95e2dd528a6db4329387d823be14bdf5089da]) Removed FCKeditor as a selection under Site Configuration. [#64 Deprecate FCKeditor ] https://github.com/exponentcms/exponent-cms/commit/95c95e2dd528a6db...

(from [0e03def5efca8cceb0d5fdda4f501b2f21ff7e67]) Moves ckeditor to inside the external/editors folder [#64 Deprecate FCKeditor ] https://github.com/exponentcms/exponent-cms/commit/0e03def5efca8cce...

(from [9c3dd9bc84f6e620a78d3b96312aa13afd767ff5]) Even though it's deprecated, restores some files needed for FCKeditor to still work. These were formerly in the themes/common/editors folder and have been moved to external/editors for the time being. Though FCKeditor is NOT supported, nor is it available as a choice under site configuration (2.0 stable)...this will provide for some measure of upgrade compatibility if there's still someone on the planet actually using exponent 2 w/ FCKeditor. This can be removed post-2.0 stable just like the 1.0 themes compatibility layer [#64 Deprecate FCKeditor] https://github.com/exponentcms/exponent-cms/commit/9c3dd9bc84f6e620...

(from [c0f3a82709f998cd1bcb934b22eaa7bc4e24c292]) Additional edit to help FCKeditor control find the template [#64 Deprecate FCKeditor] https://github.com/exponentcms/exponent-cms/commit/c0f3a82709f998cd...