Add CHANGELOG

Fixes issue #118
Add a note how old_passwords can be enabled

+other small changes
Change old_passwords markup
Merge pull request #128 from go-sql-driver/changelog

Add CHANGELOG
New DSN parser

+ Set right default addr for net=unix

Go 1.2RC1
BenchmarkParseDSN_new     200000             10545 ns/op            4039
B/op      42 allocs/op
BenchmarkParseDSN_old      10000            233313 ns/op            7588
B/op      91 allocs/op

Go 1.1
BenchmarkParseDSN_new     200000              7940 ns/op            4204
B/op      42 allocs/op
BenchmarkParseDSN_old      10000            264115 ns/op            8083
B/op      91 allocs/op
Escape DSN param values

Not really a behavior change, since it was mostly broken before
DSN param values must be escaped
Fix protocol parsing
Merge pull request #130 from go-sql-driver/dsn_parser

New DSN parser
New parameter documentation
added Amazon RDS example.

I wasted my time to setup Amazon RDS. I think this example is useful to others.
Merge pull request #131 from dalinaum/master

added Amazon RDS example.
Add Contributing Guidelines
Merge pull request #132 from go-sql-driver/contributing

Add Contributing Guidelines
use the connection buffer for writing
writeExecutePacket: fix capacity check
writeExecutePacket: fix packing
various refactoring
more refactoring

Try to remove unnecessary indirections and initialisations with zero.
Also update links to the MySQL doc
Add an Exec Benchmark

Very useful for profiling and comparing to Query