Issue 1401: Text color for white-theme buttons.

Currently the buttons do not have an explicit text color. This works if
the device default theme has a proper color for the text by default, but
fails if the default color is not readable.

This commit makes the color explicit and therefore makes it the same on
all devices.
Merge branch 'v2.1-iss1401' of git://github.com/flerda/Anki-Android into v2.1-dev
Merge branch 'v2.1-dev' into v2.1-dev-ospalh-special
Options group management
Merge pull request #11 from ntsp/Add/Remove/Reset-Options

Options group management
Reorder cards according to default group order when deleting options group.
Merge pull request #14 from ntsp/conf-del-sorting

Reorder cards according to default group order when deleting options group
Fix sync issue with multiple users on android 4.2 (issue 1609)
Merge pull request #15 from Prom42/storage-fix

Issue 1609: Fix sync issue with multiple users on android 4.2 tablets.
Merge branch 'v2.1-dev' into v2.1-dev-ospalh-special
Set a few defaults just the way i like them.
(Not whiteboard on. Looks like that doesn't work that easily.)
Revert "Set a few defaults just the way i like them."

This reverts commit 84d4ab86dde602050e96fc647a771f63360541f9.
This should fix problems when you don't switch on the whiteboard in the settings.