Fix unicity problem in "nih install PKGNAME"
better regexp for name2base
Revert "better regexp for name2base"

This reverts commit 24dff8aab0916d45c31538c81926cc63caac0934.
Fix for longstanding bug with finding correct dependencies
nih install: new options -v and -V
pkg_status: better messages
Addon for ddcb731cecba1198154350099557e926d201f773
details: "-->" statement is printed before d:/c:/whatever error messages
NIH_<subcommand>_OPTS variables were introduced
NO_REQPROV_CHECK and NO_REQPROV_CHECK variables were removed.
Use NIH_INSTALL_OPTS instead.
NIH_OPTS config variable was introduced
nih mark: new option -n was added
"nih uninstall" does not need "nih refresh -b". Thanks to Andrey N. Oktyabrski for the report!
comment in function summary_exists