Add Config flag for max returned rows

See https://github.com/nadavkav/moodle-block_configurablereports/commit/181b56df5372000e2d7d42900cb720be70c8b328 and next pull request
Add config option to settings.php

Also see next merge request
Last pull request max rows
Merge pull request #18 from DBezemer/patch-1

Add Config flag for max returned rows
Merge pull request #20 from DBezemer/patch-3

Last pull request max rows
Merge pull request #19 from DBezemer/patch-2

Add config option to settings.php
New column plugin, user final grade in current course
Initial support for 2.7
Fixed missed global declaration
Version name added
Fixed connection errors due to remoteDB
Layout fixes
New user field full name and several bug fixes
Userd field filter not unique
update missing capability

capability:myaddinstance (moodle 2.6+)
fix missing 'myaddinstance'

and correct one mistype
Check constant existence before defining it

Reference issue #23
Merge pull request #24 from Mihailoff/patch-1

Check constant existence before defining it
Merge pull request #21 from lengyelke/CR_23_STABLE

Missing capability (add instance my page)
Fixed plot graph with series names with html entities