temperature_: fix for F units

Closes #371
assp-message-statistics: fix typo

Closes #167
assp: fix typo

Closes #168
dovecot: Use DERIVE to avoid ugly computations

Using a timed grep with a state computation is usually mostly wrong. The DERIVE
field type is specifically designed for that very purpose.

Closes #264
dovecot: avoid using sort & wc when grepping

egrep has the -c option, that does a wc -l.
Also, there's no need to sort the output prior counting it.
* snmp__apc_ups2_ is in fact snmp__ups_ - a plugin for UPSes that supports the UPS-MIB
* Rather complete rewrite of snmp__apc_ups3_ script: All perl, all multigraph, one plugin to graph it all.
Add table_prefix to registered_users query
Fixed env section of manual(doc)
Fixed env section of manual(doc)
Fixed env section of manual(doc)
Fixed env section of manual(doc)
Fixed env section of manual(doc)
Allow also digest auth mechanism.

Currently only basic auth was supported. I added the ability of doing
digest auth (via 'env.auth_type').

Also, I fixed a bug where 'env.status_url' was ignored.
Merge pull request #386 from Necoro/lighty_digest

lighttpd: Allow also digest auth mechanism.
add executable flag
Merge pull request #387 from caseycs/add_executable_flag

add executable flag
Merge pull request #385 from slashsBin/master

Fix a Bug and Improved doc comments