Changed exadrums_libtool_version_info from 0:0:0 to 1:0:0, as the new version of TriggerParameters breaks the ABI.

Generate exadrums.pc from Makefile instead of ./configure, in case
prefix is overriden on the Make command line.

Make `make maintainer-clean` and `rm .gitignore && git status`
consistant.

Distribute Roadmap.md bootstrap exadrums.pc.in.

No AC_DEFINEd variable is actually used. The logs are a bit more noisy
(-D* instead of -DHAVE_CONFIG_H) but there are two files less to
generate and clean.

It documents the step from `git clone` to `./configure && make`.