Add a ignore_unknown node-level directive, allowing to selectively ignore unknown values when running munin-limits.
Also ignore transitions from UNKNOWN to OK.
Don't bail out, just prevent the state from changing.
master: do not use -p $port if unset in ssh url

If the port part is not specified in the address url, we should not
substitute it to 22.

This enables the choice to be made in /etc/ssh/ssh_config
master: adding translucent AREA+STACK
travis: adding perl 5.18
travis: build the master branch
node/t: adding some time to the test

Perl 5.18 takes longer than previous versions
Update snmp__df.in

Handle large partitions
travis: adding a dep on dbd::sqlite
remove several race conditions around lock file by opening it once
syntax fix
Merge branch 'pr/151'

Conflicts:
	plugins/node.d/snmp__df.in
doc: add munin(7) man page
doc: add munindoc(1) man page
doc: add munin-node-configure(1) man page
doc: add reference to munin-cgi-datafile

 - this man page is not written yet
doc: add SEE ALSO link to munin(7)
Merge branch 'pr/118' into devel
Merge branch 'pr/111' into devel