Made compatible with latest tip version of Go in pre 1.1 stabilisation
phase. Mostly involved fixing references to old Go package interfaces.

Interface changes were:
Converted GetInt to GetInt64
WriteConfigFile now takes a uint32 for file permissions (0644)
Removed Makefile and update README
Expanded README using the comments in the .go file
Changed package name to goconfig
Tidied up error messages
Merge pull request #3 from microcosm-cc/master

Updated to the latest version of go