Update protobuf generated files.
Update git ignore patterns.
BREAKING: Rename Node.Id to Node.ID.

For consistency with Way and Relation.
BREAKING: Do not use slice of pointers.

http://go-talks.appspot.com/code.google.com/p/go-conc/trunk/slides/goruntime.slide#27
Add test and benchmark.
Typical fileblock contains 8000 entries.
Better test and benchmark.
Rename method.
Extract method with minor optimizations.
Use repeated string for better performance.
Remove extra conversions.
Add README about our change in proto.
Merge branch 'stringtable' into refactor
Merge branch 'refactor'
Merge pull request #2 from AlekSi/master

Optimisations to decoder by AlekSi.