Update release notes in preparation for 1.11.0 release
Add explicit suchThat to Gen.conatainerOf combinators.

This also restricts Gen.containerOf to only handle
types that are implicitly convertible to Traversable.
This is required in order to be able to inspect
simplified containers.
Update README to refer to ScalaCheck site
Small README tweak
Prop uses Gen.Parameters directly instead of Prop.Params
Use scala.util.Random instead of java.util.Random in Gen
Change def to val in parameter types etc to guard for side-effects
Update release notes
ScalaCheck 1.11.0 release
Bump version to 1.11.1-SNAPSHOT
Add Gen.uuid for generating java.util.UUID instances
Fix some incorrect scaladocs
Better coverage for Arbitrary[Option[A]]
arbOption: Generate None with a probability that shrinks with the size

Also:
- Comment explaining why we use frequency() in arbOption.
- Better name for the property testing it.
Facilitate automating release. Enable Travis CI.

This factors out the version of scala-parser-combinators to build against
as `scalaParserCombinatorsVersion`, so that builds/releases can be automated
as follows:

```
     SCALA_VER="2.11.0-M7"
   PARSERS_VER="1.0.0-RC5"
SCALACHECK_VER="1.11.0"

sbt 'set version := "'$SCALACHECK_VER'"' \
    'set scalaVersion := "'$SCALA_VER'"' \
    'set every scalaBinaryVersion := "'$SCALA_VER'"' \
    'set VersionKeys.scalaParserCombinatorsVersion := "'$PARSERS_VER'"' \
    clean test publish-signed
```
Fix issue #79

As expected, using asInstanceOf is not a good idea.
When using Gen.oneOf, the suchThat method of a generator
can be fed a value of another type. This causes a
ClassCastException since the internal sieveCopy uses
asInstanceOf to get around covariance breakage. I've
fixed this by catching the ClassCastException in sieveCopy
and returning false. This is the correct thing to do in the
current implementation, but it would be nicer to work with
the type system instead.
Merge pull request #77 from adriaanm/2.11

Facilitate automating release. Enable Travis CI.
Scala 2.11.0-M7
ScalaCheck 1.11.1 release
pom changes for Sonatype