MDL-20700 coding style cleanup - cvs keywords removed, closign php tag removed, trailing whitespace cleanup

MDL-19754 MDL-8776 MDL-19678 MDL-20314 Converting old post table to blog_entries, upgrading blog code accordingly, and tags in tag_instance table

MDL-19676 Put association section in advanced items for edit form, corrected bug in group listing, enabled commenting

MDL-20219 Deleted external blog block, and preferences link from blog_menu block. Placed these as links in settings block instead

MDL-6805  Fixed redirects in blog; MDL-6807  partially fixed use of capabilitites - it needs more testing and possibly minor fixing, the commit contains other blog bugfixes too. In general it should work exactly the same. The introduction of roles makes proper setup more difficult :-(

Expect some more fixes soon, no other bigger changes...

The API was changed slightly so that has_capability now takes the
whole $context object (we almost always have it anyway)

The $kill thing was removed.   If you want to assert a capability
then use:

    require_capability('capname', $context);

with optional variables to modify the error message

Misc bugs here and there also removed and code tidied

=======================================

WARNING:  DEV IS CURRENTLY VERY UNSTABLE.

This is a mega-checkin of the new Roles system.   A lot of changes have
been made in core and modules.

Currently there are a lot of rough edges and known problems.  We are
working hard on these .. .the reason for getting this into HEAD at this
stage is enable us to move faster (our branch was diverging from HEAD
too much).

Please keep an eye on http://docs.moodle.org/en/Roles for current status
and information for developers on how to use the new Roles system.