Fixes #78
Fixes #60

Files uploaded by the user when creating/executing a synchronous job were never
deleted after the job execution.

The same problem applied for the tables already uploaded in the database (in
`TAP_UPLOAD`) when an error occurred before the end of the UPLOAD process.

Now, in case of error when uploading one or more files, or in case of success of
the job, all uploaded files and their corresponding database tables are deleted
after the end of the job.

It is also now recommended to make DBConnection.executeQuery(ADQLQuery)
return NULL if the query has been aborted (indeed, the DBConnection is
the only one that can reliably know that fact). JDBCConnection has been
adapted consequently.

job as been interrupted not by a TimeOut (cf executionDuration) but by an
IOException.

47d36bfb
In the UWS and TAP configuration files the executionDuration has to be
provided into milliseconds. But the UWS parameter MUST be in seconds.
So now, UWS is still keeping this duration in seconds (in its
ExecutionDurationController) but TAP keeps it in milliseconds (in order
to avoid unexpected silent modification of the API) and converts it into
seconds for its controller (i.e. TAPExecutionDurationController), for the
default home page and for the Capabilities page.

request which has initiated the job creation. Actually the HTTP request is
generated as before, and then, if a job is created, it is set to the ID of the
HTTP request. This modification aims to greatly help the log analysis.

[UWS,TAP] Errors and log management improvements. Particularly, now TAP and UWS are able to manage correctly HTTP request abortions (i.e. when the user stop the request before the response has been fully sent, or when there is a connection problem or a time-out). Such abortions are considered by UWS and TAP merely as job abortion/cancel. No error is logged any more. In addition of this correction, log entries concerning the execution of a TAP sync/async job have been modified so that having more coherents messages. And stack traces of exception that occurred when executing a job (sync or async, tap or uws) are displayed just once: at the JOB END log entry, and not by the HTTP RESPONSE_SENT entry. And finally, output flush and interruption detection are made more often when writing a query result (the flush is particularly important when combining with fetch-size > 0 in synchronous mode....the sync response is then a streaming output).

[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).

[UWS,TAP] Review some log messages (in the log file but also in the error summary of a job) ; particularly stack traces are added into the error summary, but are displayed just once in the logs.

[TAP] Fix a grave error: synchronous jobs were stopped much before the specified execution duration ; the library was waiting N milliseconds, where N is the TAP execution duration always expressed in seconds.

[TAP,UWS] Manage thrown Error properly in synchronous and asynchronous jobs execution + Modify some log messages + Add log messages in JDBCConnection (for add and drop uploaded tables).

[UWS,TAP] Review the exceptions and logs management + Add log file rotation (with a configurable rotation frequency)

[TAP] Remove all generic types + Delete specific (for ResultSet) output formatters + Modify the main output formatter