NF: class visual.InstructionScreen

goal = simplify code in coder demos
design pattern = display text, wait for any key, quit on escape
RF: a couple code simplifications, esp rating scale demo
RF: better visual.InstructionScreen

simpler, and kwargs can now control the format of the TextStim
RF: add InstructionScreen() .show() method

- allows separation of instr object creation from its display / use
BF: numpy.asarray was being called without numpy being imported
ENH: Restore compatibility with wxPython 2.8

The recent switch from using wxPython's Notebook widget to FlatNotebook
for code dialog broke the compatibility with wxPython 2.8 because style
FNB_NAV_BUTTONS_WHEN_NEEDED is not available there. This prevented code
dialog from showing because an AttributeError was raised. The attribute
is not needed to make code dialog work so this was fixed by checking if
it is available and only using it if this is the case (newer wxPython).
FF: Fix NameError when using keyboard component

After recent changes it was not possible to use the keyboard component
because opening the property dialog raised a NameError. This was fixed
by using an available Sizer.
FF: Fix parameter being in wrong tab in settings

In Builder's experiment settings the optional parameter for window size
was displayed in the "Basic" tab and not the "Screen" tab where related
check box is located. This was fixed by changing category to "Screen".
ENH: Corrected comment in builder source
ENH: Comment debug print in builder source
Merge pull request #457 from djmannion/master

BF: numpy.asarray was being called without numpy being imported
Merge pull request #458 from philippwiesemann/fix-builder-compatibility-wxpython

ENH: Restore compatibility with wxPython 2.8
DOCS: insert info about FF tag in git repository
BF: Fix ReadmeFrame not showing again after close

After closing (and not just hiding) the ReadmeFrame in Builder it was
not possible to show it again using the "toggle" option in the "view"
menu. The ReadmeFrame removes its reference from parent when closing.
Using the menu entry then caused an AttributeError. This was fixed by
checking the attribute (which exists because of __init__) and calling
updateReadme() and showReadme() if it does not contain a ReadmeFrame.
Merge pull request #461 from philippwiesemann/fix-builder-readme-toggle

BF: Fix ReadmeFrame not showing again after close
Merge pull request #460 from philippwiesemann/fix-builder-settings-category

FF: Fix parameter being in wrong tab in settings
Merge pull request #459 from philippwiesemann/fix-builder-keyboard-crash

FF: Fix NameError when using keyboard component
ENH: builder components now using tabs for (optional) param categories
BF: movie autodraw
ENH: only setNameColor (for extended code params) if name exists