Adding Qt5 base

Adding Qt5 base

Crosscompile and package Qt5 (base) and setup an
environment to easily crosscompile and package
other qmake based projects.

Please see the comments within the Makefiles
(Makefile / qmake.mk) for current limitations and
known issues.

Packaged from the "base" submodule herewith are:

 - qt5base-concurrent
 - qt5base-core
 - qt5base-gui
 - qt5base-network
 - qt5base-printSupport
 - qt5base-sql
 - qt5base-test
 - qt5base-widgets
 - qt5base-xml
 - qt5base-plugin-bearer-generic
 - qt5base-plugin-input-evdevkeyboard
 - qt5base-plugin-input-evdevmouse
 - qt5base-plugin-input-evdevtablet
 - qt5base-plugin-input-evdevtouch
 - qt5base-plugin-imageformats-gif
 - qt5base-plugin-imageformats-ico
 - qt5base-plugin-imageformats-jpeg
 - qt5base-plugin-platforms-linuxfb
 - qt5base-plugin-platforms-minimal
 - qt5base-plugin-platforms-offscreen
 - qt5base-plugin-sqldrivers-sqlite
 - qt5base-examples