Avoid unnecessary src dir removal
Fix #36 Use $BASH, not $SHELL
Default jobs to number of CPUs
Document NAVE_CONFIG env
Read NAVE_CONFIG array from env when building
Properly source rcfile when running a command directly
Set global prefix, as well as binroot/etc.
Only execute .bashrc if not a login shell
Also, set a version in the builtin naverc, so that we can
safely make changes to it, and be sure that they'll be
overwritten when nave is updated.
Work around cases where PATH is set explicitly in .bashrc
Fix #32 Print informational stuff to stderr
Handle curl failures properly
Abstract out build() method
Prefer the v1.2.3/node-v1.2.3.tar.gz urls
Re-use build code across install and usemain functions.
fix another easy mistake
Default jobs to 2 everywhere
Add line about bash requirement