Add alpha support of calendar icon

Add alpha support of calendar icon

Additional calendar icon support

0.3.5

Minor patch to podspec and removed an unused variable

Roll podspec deployment target back to iOS 7

Roll podspec deployment target back to iOS 7 to support existing clients.

Added some new features

Added some new features

Add accessibility tags

0.3.2

Rev to 0.3.2

Start and End values now centered.

0.3.1

Rev to 0.3.1

Tab labels now resize

Fixes issue where Start and End values need to resize when changed.

Start/End labels are now mutable.

Can now change the labels ("the strings on top") in addition to the values ("strings on bottom") to taste or for localization, etc.

Date titles no longer consume taps

0.1.1

Date titles no longer consume taps

Can now set mode programmatically.

Demo project shows how to set mode programmatically.