This is the main part of a change to add breakpoint save and restore to lldb.

Still to come:
1) SB API's
2) Testcases
3) Loose ends:
   a) serialize Thread options
   b) serialize Exception resolvers
4) "break list --file" should list breakpoints contained in a file and
   "break read -f 1 3 5" should then read in only those breakpoints.

<rdar://problem/12611863>

llvm-svn: 281273