libshell: Cleanup
Refactor|libshell: Moved MonospaceLineWrapping to its own source file

Also, some minor cleanup.
Fixed|libgui|Font: Measuring text is a const operation
Refactor|Rule: Added valuei() for accessing value as integer

Rules are floating-point, but in many cases it is more convenient
to query the value as an integer.
Fixed|libdeng2|Bank: Handling a failed load attempt

The semaphore must always be posted or the loader would wait forever.
Cleanup|Bank: By default Bank items have no size

The assumption is that by default the cache is limited by number of
items rather than their size.
libgui: Cleanup
libgui|GLTexture: Querying the maximum allowed texture size
libgui: Added GLShaderBank

Bank for storing shared GL shaders and building GL programs out of them.
Client: Load shader definitions, automatic GuiWidget initialization

GuiRootWidget also owns a large atlas for all UI images.