Upgrade LyX to v2.1.1

Would prefer it if the .sig files was also verified against, see #164.
ftp://ftp.lyx.org/pub/lyx/bin/2.1.1/
ftp://ftp.lyx.org/pub/lyx/bin/2.1.1/LyX-2.1.1+qt4-x86_64-cocoa.dmg
ftp://ftp.lyx.org/pub/lyx/bin/2.1.1/LyX-2.1.1+qt4-x86_64-cocoa.dmg.sig

Edit: URL format has changed. Got a timeout during test installation, but thought it was temporary. Updating patch.