make it possible to disable XML schema usage

Removing XML schema functionality reduces the size of
libQt5XmlPatterns.so considerably:

Linux desktop release mode:

with XML schema:    4.3 MB
without XML schema: 3.2 MB

BlackBerry10 release mode:

with XML schema:    2.6 MB
without XML schema: 1.9 MB

XML schema might not be used, especially on a mobile / embedded
device, as opposed to the rest of xmlpatterns (e.g. XPath through
QML XmlListModel).

Task-number: QTBUG-28068
Change-Id: I5024a822179e7241e592f079efe3adef8f661c70
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Bump MODULE_VERSION to 5.2.1

Change-Id: Ieb54e9508f48cc9694bd9a59dc9908cf84a62486
Reviewed-by: Matti Paaso <matti.paaso@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Sync source and generated versions of the query parser.

The following manual changes to qquerytransformparser.cpp were not
reflected in the .ypp source, but they are now:
  c95a0e6e8eb8ba5fd2a4412b318ad998b3ccb4fc (Nov 2009)
  c1623a0d42c9869e5a1d04081e7660722a863de5 (Apr 2012)

The following change is lost because it modified code generated by
bison (not from .ypp) and needs to be re-applied:
  e7a51b138772cb453555d27f44e6a2c0e79e799c

Change-Id: I72e76732acd1c370394c9fc373522b43ace6e009
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Fix MSVC2010 warnings.

Change-Id: I081b4ebad362d99dcae594f877592f2a910002f3
(cherry picked from commit e7a51b138772cb453555d27f44e6a2c0e79e799c)
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Filetree-example: Fix sort order.

The debug version of the algorithm in MSVC performs a check
on the less-than function (if a < b, b < a should be false).
Always returning QXmlNodeModelIndex::Precedes fails that.

Task-number: QTBUG-35525

Change-Id: I2ad030284eb76fd07427ffb710b3d3afd63103e5
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>
Enable -Werror for all of qtxmlpatterns

Change-Id: Ic385a3589c3c84fdd7e0c73f69ac319d0543009c
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Remove unused static functions in QtXmlPatterns

Found by Clang 3.4.

Change-Id: I60f78b62d2ecacf58d534623eced537ca62a2405
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Remove unused variable, found by ICC 14

qxslttokenizer.cpp(700): warning #177: variable "val" was declared but never referenced
              const QStringRef val(m_currentAttributes.value(CommonNamespaces::XML, QLatin1String("space")));
                               ^

Change-Id: Ic806bf1e9c22ead8680907b0e22794d7b07dcc90
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>