document plugins-c/common.h
adding gpl-*.txt in the tarball
mpc: add some whitespace in plugins-c/common.h
reorg all source code to be under src/

Makes things much cleaner
mnc: adding a test plugin for environment

use it with "munin-node-c -d t/"
mnc: adding some env vars for plugins
mnc: provide MUNIN_MASTER_IP
fix autotools usage

 * Add Makefile.am to each subproject, so make can be invoked from
   subdirs
 * Do not pass unneeded -DPLUGINDIR to munin-plugins-c
 * Fix "fails to make twice in a row". The all-local target used wrong
   link test
 * The binaries are now located in subproject directories. Adapt paths
   in .gitignore and elsewhere.
do not duplicate list of plugins
gitignore output exe
Merge remote branch 'helmut/fix-autotools-usage'
node: avoid useless recomputation
node: don't reimplement strdup
node: initialize static env vars just once
node: provide a client_ip in inetd mode
node: always flush stdout before reading

 * flush after first printf
 * also flush after using continue;
node: minor improvements based on splint analysis
Merge remote branch 'helmut/node-improvements'
node: do not segfault on plugindir open failure
node: abort() on malloc failure