- Generic content modification scheme:
Each feature has its own applicability flag that is set
from csp->action->flags.
Replaced the "filtering" int flag , by a function pointer
"content_filter" to the function that will do the content
modification. If it is != NULL, the document will be buffered
and processed through *content_filter, which must set
csp->content_length and return a modified copy of the body
or return NULL (on failiure).
- Changed csp->is_text to the more generic bitmap csp->content_type
which can currently take the valued CT_TEXT or CT_GIF
- Reformatting etc
- Removed all #ifdef PCRS