lttng: Add configuration files to call LTTng-Analyses scripts

lttng: Add configuration files to call LTTng-Analyses scripts

This patch implements configuration files to offer calling
LTTng-Analyses scripts [1] from Trace Compass.

The `index.properties` file contains a single property, `analyses`,
which is a whitespace-separated list of names of configuration files,
without the extension, to load in order to create as many LAMI
analyses.

Each configuration file contains two properties:

  * `name`: Display name of the analysis.
  * `command`: Full command to run. This string supports
    double-quoted arguments to allow arguments with whitespaces,
    or empty arguments. The `\` and `"` characters must be
    escaped with `\`.

Both properties are mandatory.

LTTng-Analyses 0.4 is supported, however 0.5 and up are recommended
since these will offer a proper progress bar and cancellation
mechanism.

[1] https://github.com/lttng/lttng-analyses

Change-Id: I3e3f7c0e8b29f1714df1f2e3acd685fc23b51e7d
Signed-off-by: Philippe Proulx <pproulx@efficios.com>
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/72101
Reviewed-by: Hudson CI