BETA

* reduce bar spark frame level
* re-enable castbar shield by default
* increase default castbar shield size slightly
* increase default castbar height slightly
* change default spell text vertical offset
* bottom component of target glow now ignores alpha
* target arrows now ignore alpha
* target arrows no longer avoid the spell icon
* change castbar shield texture
* change target arrows texture
* increase default target_arrows_inset

* add classpowers vertical offset option
* add castbar_shield_size (not exposed)

