Start porting MAPI library from MonetDB Python driver

ported, untested

- get bytes
- put block
- get block
- challenge response
- login
  - empty prompt: ok
  - ok prompt: ok
  - redirection: ok
    - merovingian: ok
    - monetdb: ok
- disconnect: ok
- cmd: ok
Query proof of concept
Use own data types for Time and Date
go fmt
Use MonetDB's prepared statement feature
Update integer conversions
Remove debugging
Use reference
Add support for transaction
Add connection string parser

Format:

   [user[:password]@]hostname[:port]/database
Update connection string parser
Add connection string parser unit test