This commit reverts commit 89418d13.

The reverted commit will be applied in another branch (probably 'adql-2.1') as
it is part of the next release of ADQL-Lib.

- Now, `ADQLParserFactory.createParser(...)` should be used to create a parser
- Only the new function `LOWER` is supported for the moment
- Not yet possible to manage the optional features _(next dev to come)_
=> 1st step for ADQL-Lib v2.0

- TAP adapted so that using the last stable version of the ADQL language
  (i.e. 2.0 for the moment)
  - but not yet possible to set the ADQL version to use in the configuration
    file

`org.json` was included in the sources of UWS-/TAP-Lib because of a manual
small correction. This is no longer needed. So this library is now a dependency
(included in the generated JAR). This has also been upgraded to the version of
August 2018.

_This commit aims to reproduce the original content of the Pull Request #38
 by @vforchi ._

The Gradle build file, the ANT build file and the README have also been updating
so that reflecting this upgrade as well as the migration from
com.oreilly.servlet to Apache Commons File Upload.

TAPLib versions of the former commit have also been fixed.

Before, the scripts relied unfortunately on the compilation performed by
Eclipse. Now, all the JUnit test cases are compiled all the time before
performing the JUnit validation (i.e. ANT task named `junitValidation`).

with additional information about dependencies, JUnit and ANT scripts.