Add frequency-based trips to transit index
calltaker module: convert html to plain text when writing mailables letter (follow up to #1160)
added agency logo (TriMet logo) for PDF generation (mailables)
Use TraverseMode.WALK in all transfer edges
Allow for GTFS transfers in LongDistancePathService's PathParser
Alter PlanGeneratorTest to reflect requirements of Beter Benutten MMRI tests
Copy stop id information around in PlanGenerator
Reverse optimize twice
Use TraverseMode.WALK consistently in TransferEdge
patch from larentg removing apache commons exclusions from POM

resolves issue reported by Simone B. on dev list
https://groups.google.com/d/msg/opentripplanner-dev/XtDFK0tB4pI/6PReIUhmpL0J
Merge remote-tracking branch 'upstream/merge_modules' into merge_modules
Add an explanation about the double reverse optimization technique
Assume that stops can be boarded with wheelchairs by default (defer to per-trip data)
Merge remote-tracking branch 'upstream/merge_modules' into merge_modules
Accept only TransitStops for TransferEdges

These four commits demonstrate a new paradigm I just made up called type safety driven design.
Improve type safety of GtfsStopContext

These four commits demonstrate a new paradigm I just made up called type safety driven design.
Fix compilation errors

These four commits demonstrate a new paradigm I just made up called type safety driven design.
Disallow chaining of TransferEdges

These four commits demonstrate a new paradigm I just made up called type safety driven design.
Add stop ids to more legs to make Beter Benutten MMRI people happy
Allow paths starting and/or ending with transfers