Add JSON support for output format.

JSON format is good for sharing data with other languages, which makes
it easy to integrate pgBadger's result into other monitoring tools
like Cacti or Graphite.
Fix bad URL to documentation. Thanks to Rodolphe Quiedeville for the report.
Merge pull request #170 from rodo/master

Two minor change to made easier to use Tsung scenario
Fix issue with csv log format and incremental mode. Thanks to Suya for the report and the help to solve the issue. There also a fix to support autovacuum statistic with csv format.
Merge branch 'master' of github.com:dalibo/pgbadger
Add execute attribute to pgbadger in the source repository, some may find this more helpful when pgbadger is not installed and executed directly from this repository.
Merge branch 'master' of github.com:lansz/pgbadger into lansz-master
Merge branch 'lansz-master'
Add minimal documentation about JSON output format.
Fix missing database name in samples of top queries reports. Thanks to Thomas Reiss for the report.
Fix overcount of sessions when a client attempts to log in and is kicked off because of failed authentication or an incorrect database name. These show up as sessions which connected and never disconnected. Thanks to Josh Berkus for the report.
Fix remote ssh command error sh: 2: Syntax error: "|" unexpected. Thanks to Herve Werner for the report.
Fix incorrect location of temporary file stroring last parsed line in multiprocess+incremental mode. Thanks to Herve Werner for the report.
Allow/improve incremental mode with multiple log file and multiprocess.
Fix missing initial move to offset in incremental mode before the file change test. Thanks to Herve Werner for the report.
Fix move to offset in incremental mode with multiprocess and incomplete condition when file is smaller than the last offset.
Fix an other issue with wrong offset in incremental mode, initial position was 1 instead of 0. Thanks to Herve Werner for the report.
Fix incomplete handling of XZ compressed format.
Allow pgBadger to write out extra files to outdir when creating incremental reports. Require the use of the -X or --extra-files option in incremental mode (-I). Thanks to Matthew Musgrove for the feature request.
Fix wrong move to begining of a file if the file was modified after have been parse a time. Thanks to Herve Werner for the report.
Add a copy icon in front of each query in the report to select the entire query on click. Click and drag to select the query can be a pain, this button is a click-to-select that allow to use Ctrl+c to copy on clipboard. Thanks to Josh Berkus for the feature request.