Add reader field to Logstream type
Use a gzip reader if needed when opening logs

Uses file extension to guess whether a log file is gzipped.

If so, a gzip reader is used. If not, the file descriptor is used
as the Logstream.reader.
use os.FindProcess instead of sys call.Kill
Make createFileReader private and extract isGzipFile
Modify SeekInFile and FileHashMismatch to handle gzipped files

Previously, Seek was used on the current fd to seek to the
penultimate line in the file and hash the last line.

Where the current file is gzipped, consume bytes from the
gzip reader to give the same effect as Seek.

This creates unnecessary garbage but is probably the simplest
way to emulate Seek.
Only compare file size and seek position for non-gzipped files

Number of unzipped bytes read will often be greater than the file size.
Use strings.HasSuffix to determine whether path ends in .gz
Clarify createFileReader doc
Remove extraneous gzip check in SeekInFile
Remove unneeded comparison in isGzipFile
Merge pull request #809 from mattcottingham/feature/gzip-logstreamer

Support reading of gzipped files with logstreamer
add item to changelog
mention the issue number
Turn the MySQL slow query log examples into a deployed decoder and filter

- Additional documentation cleanup
Fix doc typo
Fix the matcher benchmarks to test the match condition
Issue #767 Fix TcpOutput test hang

The output was being shutdown after the message was queued but
before it was sent causing the test to wait forever for the result.
Update manager.rst

Update the tutorial's TcpInput configuration.
Only check for backpressure on dynamic sandbox plugins

On startup the system is slammed by all the plugins contending for resources
which can skew the backpressure sample timing by over 200x.  Occasionally this
causes static sandboxes to be terminated as 'running too slowly'.  Static
sandboxes should be considered part of the system, trusted and therefore
exempt from this check.
Merge pull request #821 from mozilla-services/mysql_slow_query

Turn the MySQL slow query log examples into a deployed decoder and filter