Add method chaining support to QB cache methods
Add method chaining support ot CI_DB_query_builder::reset_query()
[ci skip] Update Query Builder docs

Close #2512
Related: #3396
[ci skip] Update DB result docs

Related: #3395
changed theme to sphinx_rtd_theme

Signed-off-by: David Wosnitza <david@druul.in>
exchanged colors

Signed-off-by: David Wosnitza <david@druul.in>
fixed indentation/linkref errors

Signed-off-by: David Wosnitza <david@druul.in>
reverted changes on source/index.rst

Signed-off-by: David Wosnitza <david@druul.in>
rebuild and optimized toctrees

Signed-off-by: David Wosnitza <david@druul.in>
added original license to theme
increased top and bottom margins for printing

Signed-off-by: David Wosnitza <david@druul.in>
increased bottom margin

Signed-off-by: David Wosnitza <david@druul.in>
[ci skip] Remove an unused lang string

Close #3411
Merge pull request #3410 from druu/feature/userguide_redesign

Feature/userguide redesign
removed max-width from docs content
Merge pull request #3412 from druu/patch-2

removed max-width from docs content
Remove output minifier

This feature has proven to be problematic and it's not nearly
as flexible as a dedicated minifier library like Minify
(http://www.minifier.org/, https://github.com/matthiasmullie/minify).

The same results in terms of saving traffic can also be achievied via
gzip compression (which should also be done on the httpd level, but we
also support anyway) and stuff like mod_pagespeed.

Reverts PR #965

Related issues as a track record proving how problematic this has been:

#2078 #1499 #2163 #2092 #2387 #2637 #2710 #2120 #2171 #2631 #2326 #2795
#2791 #2772

Additionally, the count of contributors suggesting that the only way
to fix the minifier problems is to remove it, is around the same as
the count of people suggesting the feature to be implemented in the
first place. It was experimental anyway ... the experiment failed.
Remove minifier test
User Guide - DB Driver Reference

First stab at DB driver reference. Methods are listed in order encountered in the source file.
Parameter or return types in DB_driver updated as needed, and reflected here.
TOC entry added to bottom of database index page.
Signed-off-by:James L Parry <jim_parry@bcit.ca>
Fix Issue #3417