Change the encoding of the Triple string exchanged across GDB-RSP
and update documentation to suit, as suggested by Jason Molenda and
discussed in:

http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140721/011978.html

Differential Revision: http://reviews.llvm.org/D4704



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@214480 91177308-0d34-0410-b5e6-96231b3b80d8