LogFile tells LogEvent when year_rollover occurs. First step to removing mandatory datetime parsing.
set datetime_format and datetime_nextpos from previous log lines to current one. Step 2 in skipping mandatory datetime parsing.
fixed edge-case where field name wasn't correctly wrapped in quotes.
some small fixes in the query section in case groups return empty. LogFile provides hints to LogEvent about timezone format and the offset.
Use file position rather than datetime of current line to determine if `--to` has been reached.
optimization to parse single files faster. Not quite working yet, needs more testing.
more fixes for fast log parsing. needed to move from next() to readline() on file handle due to internal readahead buffer.
more logfile changes. everything reads with self.next() now, which will take care of year rollover and datetime hints.
added ValueError if to < from.
rewrite of DateTimeBoundaries. Simplified, using dateutil parser for most of the parsing.
added tests for DateTimeBoundaries.
added more tests for DateTimeBoundaries
added "yesterday" constant. better comments.
Merge branch 'develop' into feature-187-notimeparse
latest code coverage stats.
mplotqueries now uses the new Grouping class.
added argument --no-others to disable "others" group when using --group-limit.
fixed None labels, renamed to ' ' (space).
Merge branch 'develop' into feature-187-notimeparse

Conflicts:
	mtools/test/cover/index.html
	mtools/test/cover/status.dat
added variable parsing for log2code from Shraya.
Merge branch 'feature-log2code-variable' into develop
added index to logcodelines, index is the order in the log2code.pickle database.
it's also now an OrderedDict, but as interface is the same.