Extended locales in AAPT / AssetManager.

Extended locales in AAPT / AssetManager.

Support 3 letter language codes, script codes &
variants. The bulk of the changes are related to
the implementation of command line filtering of
locales etc. The previous code assumed that the
value of each "axis" (locale, density, size etc.)
could be represented by a 4 byte type. This is
no longer the case.

This change introduces a new class, AaptLocaleValue
which holds a (normalized) locale parsed from a
directory name or a filter string. This class takes
responsibility for parsing locales as well as
writing them to ResTable_config structures, which is
their representation in the resource table.

This includes minor changes at the java / JNI level
for AssetManager. We now call locale.toLanguageTag()
to give the native layer a well formed BCP-47 tag.
I've removed some duplicated parsing code in
AssetManager.cpp and replaced them with functions on
ResTable_config. The native getLocales function has
been changed to return well formed BCP-47 locales as
well, so that the corresponding java function can use
Locale.forLanguageTag to construct a Locale object
out of it.

Finally, this change introduces default and copy
constructors for ResTable_config to prevent having
to memset() the associated memory to 0 on every
stack allocation.

Change-Id: I899a56a9a182ee6be52b9389d1ae59266f5482e9