Help forward compatibility by ignoring invalid KeyValues.

Right now all data points are written with 2-byte qualifiers.  When we
compact data points, we paste together the qualifiers, so we end up with
a multiple of 2 bytes no matter what.  So when compacting a row, only
consider those KeyValues that have a qualifier that is even and has 2 or
more bytes, and silently ignore the rest.
Upgrade to Junit 4.11.

Also fix the URL from which it's being downloaded, as the GitHub URL
unfortunately became invalid.  Fetch from Maven instead, it's safer
in the long term.

This closes #158.
Add an RPM spec file.

Automatically set the version via configure.

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>
Make it easier to build an RPM from source.

Add an `rpm' target to the Makefile that creates a tarball of the
current sources, and uses it to build an RPM.  Also fix various
issues to be able to build on Fedora and neuter various RPM macros
that are sometimes overridden and make life unnecessarily painful.
RPM: Improve formatting of the %description.
Don't urldecode the components, assume the URL is already decoded.

This fixes #152.

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>