Update postgres.d

fix build when not using vibe.d
Merge pull request #15 from adamdruppe/master

Update postgres.d
implement text binding for params
Merge pull request #16 from adamdruppe/master

implement text binding for params
bug in length calculation with >1 text params
looping params needs to be sorted since otherwise the formats can get out of order when looping to build the message
Merge pull request #17 from adamdruppe/master

bugs
Merge branch 'master' of https://github.com/pszturmaj/ddb