`fix_on_fail` in the configuration file. By default, this feature is disabled.

_With 15cd5944, this commit finishes the resolution of the GitHub issue #104 ._

The property `upload_default_db_limit` has been deprecated. Indeed, in the
current state of the TAP protocol, this makes no sense: the user can not change
the limit size (in bytes or rows) for uploaded tables.

The property `upload_max_file_size` has been deprecated. It is actually
duplicated: `upload_max_db_limit`, if expressed in bytes already lets put a
limit on the maximum size of an uploaded table/file.

The property `upload_max_request_size` has been added. It lets set a maximum
size for a whole HTTP Multipart Request. By default it is set to 250MB.

The default value of `upload_max_db_size` is now 1 million rows.

The UPLOAD feature is still disabled by default (i.e. `upload_enabled=false`).

Two embedded DBMS are used: H2 and a little SQLite. JDBC drivers are provided
in the `lib` directory. The databases are created and deleted automatically
by the JUnit tests (see `test/tap/db_testtools/DBTools for more details`).

The ANT and Gradle build scripts have been updated to reflect all these test
modifications.

[TAP] Incorrect setting of the backup frequency. The documentation was also incomplete about this property, but also wrong concerning the property backup_mode which is actually backup_by_user.

[TAP] Add the possibility to set the FetchSize on a DB Statement for the execution of ADQL queries. It is also possible to set a fetchSize different for synchronous and asynchronous queries.

[ALL] Update ANT build scripts to test all existings JUnit tests before compiling. In case of error, the compilation does not complete.

[TAP] Add a new database access method in the configuration file: get a Datasource from JNDI. & Better support of connection pooling (TAPFactory.countFreeConnections() has been removed ; when the creation of a database connection fails with an SQLException, it is considered that no connection are momentarily available...async jobs will be queued and all sync requests will be rejected).

[TAP] Add metadata support in the configuration file. Two methods to get metadata: 1/ Parse an XML file implementing the schema TableSet, and then re-build TAP_SCHEMA in the database, 2/ Get metadata from the database schema TAP_SCHEMA.

+ Add the management of the Output Limit in TAPConfiguration
+ All the corresponding JUnit Tests
+ Replacing .properties test files for JUnit by a construction of Properties object
+ Update of the HTML documentation page and of the Full example file

TAP+TEST: First steps with the TAP configuration file management (Factory, ServiceConnection, but not yet Metadata) + their JUnit tests + documentation (the html file + configuration file examples)