Removed all Wolfram|Alpha related stuff on their request.
Linking users to WA violated their terms of use.

Signed-off-by: Mark Kamsma <mark@markkamsma.nl>
Multiple lines are no longer accepted in the favourites dialog.
Fixes #166.

Signed-off-by: Mark Kamsma <mark@markkamsma.nl>
Fixed the about dialog for landscape mode on phones (fixes #163)

Signed-off-by: Mark Kamsma <mark@markkamsma.nl>
The user can now only differentiate over a single variable (fixes #158)

Signed-off-by: Mark Kamsma <mark@markkamsma.nl>