Clean out params field in database if query doesn't contain placeholders
Added code to handle LIMIT inside sql when less than MAX_RECORDS
Added querylimit field for returning record, must be less than MAX_RECORDS constant
Fixed code in form and install/upgrade to properly use the REPORT_CUSTOMSQL_MAX_RECORDS constant
Better date handling

1. If a column in the results has a name ending in date, then values in
that column that look like integers will be displayed as a nicely
formated date.

2. If a placeholder in the query has a name ending in date, then
users will be asked to set the value of that placeholder using a
date/time picker.
Fix upgrade code.
Merge branch 'limits'

Conflicts:
	db/upgrade.php
	version.php
Re-order query edit form fields.
Increment the version number ready for the 2.4 release.