Revert "webif: Simplify template loading and checking."

This reverts commit r8346. The subdir logic is used to have different
template directories for different paths comming from http request.

For more info see:
  http://www.streamboard.tv/wbb2/thread.php?threadid=37378

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@8437 4b0bc96b-bc66-0410-9d44-ebda105a78c1