prepare v3
Be explicit about path to default PKGBUILD

Fixes GHI#12.
mkaurball: enforce sane permissions on tarballed files

There's not really any reason to set permissions to anything other than
644 or 755 (and even 755 is questionable). In the future, files will be
stored in git (where only the -x bits are stored), and this will need
to be dealt with (properly) in the PKGBUILD.

Fixes downstream bug: https://bugs.archlinux.org/task/41313
fix indenting
prepare v4 release
fix deficiencies in array_build

Copy values indirectly by index, giving us support for:

- associative arrays
- sparse arrays
- empty strings as elements
rename pkgbuild_introspection{,.inc.sh}
optimize array_build, add an error condition

Factor out the many evals into a single one by writing a small bash
program of printf -v calls which construct the new array. eval'ing
this at once brings us roughly back to the performance of the intial
single-line 'eval' statement.
changes to make it work on osx