Support for tag-driven publishing on Travis.

Modify travis build to derive the project version from TRAVIS_TAG (when set).
as well as to have sbt run the `publish-signed` task if the environment is right.
The tag must match the semver regex `^v[0-9]+\.[0-9]+\.[0-9]+(-[A-Za-z0-9-]+)?`,
and the jdk we're running on must match PUBLISH_JDK (set in .travis.yml).

For every repo, you must create the following files (not included here)
according to the instructions in admin/gpg.sbt:
 - admin/pubring.asc      (commit)
 - admin/secring.asc      (DO NOT COMMIT)
 - sensitive.sbt          (DO NOT COMMIT)
    - passphrase for secring.asc
	- api token for staging to sonatype

Generate these using `admin/encryptAll.sh`:
 - admin/secring.asc.enc  (commit)
 - sensitive.sbt.enc      (commit)

Note that `encryptAll.sh` spits out a "- secure .... " line,
that you need to add to `.travis.yml`'s `env` section, so that
travis can supply the SECRET env variable, which is used to
decrypt the sensitive files above.
Secure config for publishing to sonatype
Merge pull request #39 from adriaanm/autopublish

Support for tag-driven publishing on Travis.
Update to sbt 0.13.7 for auto-publish script.

Need better whitespace support, I think.

https://travis-ci.org/scala/scala-parser-combinators/jobs/43029096
Revert "make RegexParser.err handle whitespace like literal and regex."
Merge pull request #41 from scala/revert-30-wip/i29

Revert "make RegexParser.err handle whitespace like literal and regex."
Bump version to 1.1.0-SNAPSHOT

Also moves to Scala 2.11.4.

Mima is disabled since `1.1.0` won't be binary compatible with `1.0.x`.
There will be a `1.0.x` branch for releases that should stay binary
compatible (like the version bundled in the Scala 2.11 distribution).
Merge pull request #42 from gourlaysama/bump-version

Bump version to 1.1.0-SNAPSHOT
update README.md for 1.0.3
Merge pull request #43 from gourlaysama/readme

update README.md for 1.0.3
Fix misleading error message when using optional or repeatedly parser #34