Added property to label in order to store the theme applied. Also added methods to update the label attributes based on current theme
Register observer for changes in theme’s attributes related to label. Update the label when any attribute (or the whole theme) is changed
Updated sample to show how to change label’s attributes
Fixed wrong copy&paste /:
Removed back label’s theme property. It’s not necessary to have the theme referenced twice (from view and label)
Fixed problem setting theme’s thickness several times. Each time the tickness is changed, the label is stretched
Merge branch 'master' into update-font-changes

Conflicts:
	MDRadialProgress/MDRadialProgress/MDRadialProgressView.h
	MDRadialProgress/MDRadialProgress/MDRadialProgressView.m
Change code for resize-label fix (https://github.com/mdinacci/MDRadialProgress/pull/25)
Merge pull request #29 from jmnavarro/update-font-changes

Refactored label property. Fixed #25 and an issue with setting the theme's thickness several times.