Added enhanced buffer support
Added enhanced buffer support

Bulk transfers now use the ENHBUF FIFO system in some of the
PIC32 chips (if available).  This makes transfers faster as it
eliminates the delay between transferred bytes.

majenkotech/chipKIT-core,ricklon/chipKIT-core,pontech/chipKIT-core,UECIDE/chipKIT-core,majenkotech/chipKIT-core,ricklon/chipKIT-core,ricklon/chipKIT-core,ricklon/chipKIT-core,UECIDE/chipKIT-core,EmbeddedMan/chipKIT-core,majenkotech/chipKIT-core,pontech/chipKIT-core,pontech/chipKIT-core,adamwolf/chipKIT-core,UECIDE/chipKIT-core,EmbeddedMan/chipKIT-core,EmbeddedMan/chipKIT-core,pontech/chipKIT-core,majenkotech/chipKIT-core,EmbeddedMan/chipKIT-core,chipKIT32/chipkit-core,pontech/chipKIT-core,chipKIT32/chipkit-core,adamwolf/chipKIT-core,adamwolf/chipKIT-core,UECIDE/chipKIT-core,pontech/chipKIT-core,ricklon/chipKIT-core,chipKIT32/chipkit-core,majenkotech/chipKIT-core,EmbeddedMan/chipKIT-core,ricklon/chipKIT-core,adamwolf/chipKIT-core,adamwolf/chipKIT-core,majenkotech/chipKIT-core,adamwolf/chipKIT-core,UECIDE/chipKIT-core,EmbeddedMan/chipKIT-core,chipKIT32/chipkit-core,pontech/chipKIT-core,majenkotech/chipKIT-core,EmbeddedMan/chipKIT-core,adamwolf/chipKIT-core,chipKIT32/chipkit-core