pgsql: Update inheritance constraint items: < o %Prevent child tables

Log Message:
-----------
Update inheritance constraint items:

< o %Prevent child tables from altering or dropping constraints
< like CHECK that were inherited from the parent table
< like CHECK that are inherited by child tables
<
< Dropping constraints should only be possible with CASCADE.
<

like CHECK that are inherited by child tables unless CASCADE
is used
o %Prevent child tables from altering or dropping constraints
like CHECK that were inherited from the parent table

Modified Files:
--------------
pgsql/doc:
TODO (r1.1810 -> r1.1811)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1810&amp;r2=1.1811)
pgsql/doc/src/FAQ:
TODO.html (r1.313 -> r1.314)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.313&amp;r2=1.314)