HEAD is v0.2.
Define support for ordering dependencies.
Expand core requirement checks to more programs.
Skip reserved keyword when iterating scripts.
Add utility to list make targets.
Normalize signatures for map functions.
Support calling individual package scripts.
Fix singular/plural listing of package count.
Add utility to write Makefile from Orderfile.
Support Orderfile.
Add 'all' to reserved script names.
Release nixd v0.2.

Note that this release is for experimental support for the
Orderfile. Therefore, v0.1 will remain at branch 'master' until further
testing on GNU/Linux and Mac OS X systems.
HEAD is v0.3.
Revert to v0.1.
Use "Goals for Use" from v0.2.
Expand core requirement checks to more programs.
Normalize signatures for map functions.
Remove make & sed from dependency checks.
Re-apply relevant patches from v0.2.
Rename `nixd boot` to `nixd install`.