When recieving the intent we now check if the WANT_EXPORT extra is present

If so, we ignore the MAX_CONTACTS_NUM_TO_SELECT_ONCE value to allow 
for exporting of more than 500 contacts to storage.

Change-Id: I2692ce7fe3f1f92d31c4d21f89866d7816cccede
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Contacts into android-4.4