Added the ability to _not_ skip the prologue when settings breakpoints

by name by adding an extra parameter to the lldb_private::Target breakpoint 
setting functions.

Added a function in the DWARF symbol file plug-in that can dump errors
and prints out which DWARF file the error is happening in so we can track
down what used to be assertions easily.

Fixed the MacOSX kernel plug-in to properly read the kext images and set
the kext breakpoint to watch for kexts as they are loaded.

llvm-svn: 134990