get rid of sqlType param from FieldDef & EntityDef
un-Maybe fieldSqlType, properly set references

initially set fieldSqlType to SqlOther

the embedded references did not have their fields updated properly yet
this was because tieing the knot is difficult due to it being finished
at lift time. (It is possible, but then uses lot of RAM)

Handle the reference cycle with a simpler embed structure
That way the references don't have to deal with fieldSqlType
use fieldReference instead of stripId
Check Id suffix against existing entities

closes #83
Allows for usage of a field type with an Id suffix
Merge pull request #256 from yesodweb/SqlType

get rid of sqlType param from FieldDef & EntityDef