Mobile detect is being called too many times

[Robert Lyon]

In init we call isMobile() twice and that can be expensive. For me it meant calling Mobile_Detect::match 524 times rather than 262 times when we call it once and remember it's answer.

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/4336

[Robert Lyon (robertl-9)]

In fact checking if device is mobile only every needs to be done one per session and not once per page load - as the device is not likely to change mid stream (unless dev testing) so we don't want prod sites testing for it on every page/block/artefact load.

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/4336
Committed: http://gitorious.org/mahara/mahara/commit/9813cbb92d6b35ecf80f8b145a36a3e4b58a1fd1
Submitter: Aaron Wells (<email address hidden>)
Branch: master

commit 9813cbb92d6b35ecf80f8b145a36a3e4b58a1fd1
Author: Robert Lyon <email address hidden>
Date: Mon Mar 2 15:34:08 2015 +1300

Reducing the number of calls to Mobile_Detect->isMobile() (Bug #1427031)

We seem to be calling it on every page load - so for a page with lots
of blocks it means a lot of calls.

When really we should call it once when a user first arrives as they
won't be switching devices during their session.

Change-Id: Id939ad83c5acfdbcdd358691def25bd2e5f5a592
Signed-off-by: Robert Lyon <email address hidden>