import-package.sh git version dependency

[Jason Bacon <bacon4000%gmail.com@localhost>]

FYI, the following line in wip/import-package.sh depends on specific git 
versions:

    if ! git status -u no | grep "Your branch is up-to-date"

It fails on CentOS 6.7, which uses git 1.7.1, because the status 
subcommand produces different output.  ( See below )

Might be good to add a git version test to import-package.sh, or just 
find a new approach that's not version-dependent, to save people the 
trouble I just went through to track this down.

    Jason

~~~~

Linux sciprog2.ceas bacon ~/Pkgsrc/pkgsrc-2016Q1/wip 420: (pkgsrc): 
which git
/home/bacon/Pkgsrc/pkg-2016Q1/bin/git

Linux sciprog2.ceas bacon ~/Pkgsrc/pkgsrc-2016Q1/wip 421: (pkgsrc): git 
status -u no
On branch master
Your branch is up-to-date with 'origin/master'.
nothing to commit, working directory clean

Linux sciprog2.ceas bacon ~/Pkgsrc/pkgsrc-2016Q1/wip 422: (pkgsrc): git 
--version
git version 2.7.3

Linux sciprog2.ceas bacon ~/Pkgsrc/pkgsrc-2016Q1/wip 423: (pkgsrc): 
/usr/bin/git status -u no
# On branch master
nothing to commit (working directory clean)

Linux sciprog2.ceas bacon ~/Pkgsrc/pkgsrc-2016Q1/wip 424: (pkgsrc): 
/usr/bin/git --version
git version 1.7.1