refs #1654: First version of new standard skin

 - Work in progress.

 - We need some template language for skins.
   Currently we have to modify PHP codes to change HTML markups,
   but if we have a template engine, the modification can be confined
   within HTML only.

   Example:

     <li [##_no_more_prev_##]><a ...
     dress('no_more_prev', isset($paging['prev']) ? '' : 'class="disabled"', $view, $useSkinCache);

     can be rewritten as (following Jinja's syntax):

     <li{% if no_more_prev %} class="disabled"{% endif %}><a ...
refs #1654 : enhancement - automatic mobile skin load.
 - i/ and m/ URLs are removed.

From now on, textcube loads skin/blog/lucid when
  - blog.useiPhoneMode is true
  - device agent is recognized as the one of mobile devices.

TODO:
  - mobile <-> desktop mode button
  - move skin location to under resource/ directory.
  - upgrade skin parser to read skins outside /skin/blog directory.
  - Lots of mobile skin design / functions
refs #1654 : modified - desktop-mobile exchange button
refs #1654: work in progress
refs #1654 : modified - default skin location

 - default skin location (/skin/default) added.
 - Mobile mode uses skin at /skin/default/lucid.
refs #1654 : added - new configuration (to support mobile-compatible
	skin)

-
refs #1654 : skin resource reference point is now flexible.
refs #1654: work in progress
refs #1654: revert local-only changes
refs #1654 : modified - skincache for one-blog-multi-skin environment.
refs #1668 : removed - IE6 support code / CSS
 refs #1654 : enhanced - sidebar rendering is off in mobile mode
 refs #1544 : periwinkle skin based on persona

 - Periwinkle skin by @inniss
 refs #1544 : removed - unused jquery

 -
 refs #1544 : added - mobile support tag to periwinkle skin

 -