add LESS support

still needs testing
added missing lessc library
fixed ini replacement to less variables stuff
lessyfied the first of template's CSS files
lessyfied another one
lessified more files
make sure calculations are correct
convert ini replacements to less vars first

This makes it possible to safely overwrite ini replacements from within
any less file
removed debug statement. sorry
fixed broken structure
unlessified and lessified a few more css
switched to LESS variables in rest of template's css files
removed possibility to have rtl.less files in plugins
check less compilation for errors

This now gives proper files and line numbers for errors
Merge branch 'less'

* less:
  check less compilation for errors
  removed possibility to have rtl.less files in plugins
  switched to LESS variables in rest of template's css files
  unlessified and lessified a few more css
  fixed broken structure
  removed debug statement. sorry
  convert ini replacements to less vars first
  make sure calculations are correct
  lessified more files
  lessyfied another one
  lessyfied the first of template's CSS files
  fixed ini replacement to less variables stuff
  added missing lessc library
  add LESS support

Conflicts:
	inc/load.php
	lib/tpl/dokuwiki/css/basic.less