Add option to hide underline

This will automatically adjust the positioning of the text below to accommodate for the extra space
Tweak layout in sample activity

Added some spacing to top and bottom, consolidate laying out to parent linearlayout padding rather than repeated margin attributes in child views
Prevent keyboard from automatically showing in sample activity

This always really bugged me in testing...
Merge pull request #28 from hzsweers/master

Add option to hide underline + couple minor tweaks