Upgraded everything to Xcode 5.1.
Minor change to boot2’s build procedure.

Now, boot2 is actually called boot2 when it is installed (it was previously just called “boot”).
Removed deprecated compiler flags.

These were causing compiler errors under Xcode 5.1.
Silenced an unnecessary warning.
Silenced an ld warning.

ld was emitting warnings about use of a deprecated technique used to refer to the beginning and end of a Mach-O section. To fix this I changed the symbol references to use the more modern syntax.