some changes on DbOom

1.DbSqlBuilder can append chunk now

public DbSqlBuilder _(SqlChunk chunk)
we can use like: sql()._(userDefinedChunk)

2.Add more multi-column definition in $C t-sql macro

$C{foo.[p1|p2|...]}   equalsTo  $C{foo.p1, foo.p2,...}  

also it makes t-sql hints more sweet: “$C{boy.girlAlt:girl.[id|name]}”  instead of $C{boy.girlAlt:girl.*}” if I just need some columns，not all columns