Introduces additional steps to "admin_side" callback event.

Adds callback events:

* "admin_side > main_content"
* "admin_side > main_content_end"

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5250 2fea6a4d-a838-0410-917b-93a53c48e9d2
$txp_user isn't used in end_page().

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5251 2fea6a4d-a838-0410-917b-93a53c48e9d2
Comments panel uses require_privs() for aborting.

Fixes the invalid markup caused by missing footer too.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5252 2fea6a4d-a838-0410-917b-93a53c48e9d2
Sort error-prone SQL joins.

When joining make sure to make it clear from which table
the column should be fetched from.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5253 2fea6a4d-a838-0410-917b-93a53c48e9d2
Fix parent title searches that start with numbers.

In short, that doesn't do what it think it does. Any numeric
like value gets evaluated as TRUE. Particularly, in PHP, any
string that starts with a number becomes a non-zero
integer when casting, unless the value at the start is
considered as 'zero'.

Thus, if this check really needs to be there, it requires
casting and also comparing it to the original value in string
representation. Identical to avoid type juggling that
otherwise occurs again.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5254 2fea6a4d-a838-0410-917b-93a53c48e9d2
Array meet space.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5255 2fea6a4d-a838-0410-917b-93a53c48e9d2
Files panel uses require_privs() for aborts.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5256 2fea6a4d-a838-0410-917b-93a53c48e9d2
Fixed undefined variable in get_lang_files()

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5257 2fea6a4d-a838-0410-917b-93a53c48e9d2
Clean up install_lang_key().

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5258 2fea6a4d-a838-0410-917b-93a53c48e9d2
selectInput() sanitizes attribute values used in the HTML.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5259 2fea6a4d-a838-0410-917b-93a53c48e9d2
checkbox() finds missing docs.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5260 2fea6a4d-a838-0410-917b-93a53c48e9d2
tsi() sanitizes HTML attribute values.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5261 2fea6a4d-a838-0410-917b-93a53c48e9d2
Added example for tsi().

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5262 2fea6a4d-a838-0410-917b-93a53c48e9d2
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/philwareham/textpattern