lua: Stylistic fixes

Fix a few * placement issues and other stylistic problems. Fixes #10.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
Preparations for syslog-ng-incubator 0.1.1

NEWS updated, and version bumped in configure.ac.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
lua: #include "lua-msg.h" too in lua-dest.c

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
lua: Add an ElasticSearch script & config

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
.travis.yml: Install curl, add-release.sh needs it

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
lua: Factored out checking of global variables in state.
lua: Created convenience library from lua utility functions.
monitor-source: Added monitoring source.

Monitor source is a new source mixing the capabilities of a Lua-based
driver and the trigger source. It is periodically executing a given
Lua function. If the function returns a string, a new message is created
which contains this string as the MESSAGE part. However, when a (non-nested)
dict is returned, the key/value pairs of the dict is added as name-value pairs
to the newly created message.