introduce DEntity.keySet method

and refactor DEntity.toMap in terms of keySet
Merge pull request #27 from pellucidanalytics/topic/Entity.keySet

introduce DEntity.keySet method
prettified Build.scala
added Builder->14
Fixes #26 : in fact the parser seems to accept rule call in rules
DEntity.get(Attribute) is now brought by implicit in DatomicMapping
Fixes #25: added java.math.BigInteger/BigDecimal DDReader/DDWriter
Merge pull request #29 from pellucidanalytics/features/issue#25

Fixes #25: added java.math.BigInteger/BigDecimal DDReader/DDWriter
Fixes #26: now accepts parens in all identified cases
Fixes #24
Fixes #22: added TxReport.idMap/toString
Merge pull request #28 from pellucidanalytics/features/dentity-refact

DEntity.get(Attribute) is now brought by implicit in DatomicMapping... Let's merge it for now and see later about Ref
expose tx-report tempids in a proxy Map object (fixes #22)

TxReport.tempidMap gives a limited Map[DId, Long] interface over the tempids returned by a transaction
the implicit arguments for resolve are unneeded, we simply use the db value returned by the transaction
new parser combinators for parens, brackets, and braces (closes #26)

introduce parser combinator `wrap`, that ensures matching strings around another parser
use `wrap` to implement matches for (), [], {}, and ""
Merge pull request #31 from pellucidanalytics/feature/parser-wrapcombinator

new parser combinators for parens, brackets, and braces (closes #26)
Merge pull request #30 from pellucidanalytics/topic/txreport-tempidMap

expose tx-report tempids in a proxy Map object (fixes #22)
simplified DDReader/DDWriter variances
tidy and add to DatomicDataImplicits

added missing implicits for UUID, URI and Byte Array
make naming conventions consistent
add tests for DDReader and DDWriter
simplify Attribute2EntityReaderImplicits

code in the constructed Entity readers no longer uses _.as[T] or _.getAs[T], just direct casts
simplify set manipulation