Gets the path to the Tika App .jar installed by tika_install().
Details
The tika_jar() function also checks if the .jar is actually on the file system.
The file path is used by all of the tika() functions by default.
Alternative Uses
You can call Apache Tika directly, as shown in the examples here.
It is better to use the sys package and avoid system2(),
which has caused erratic, intermittent errors with Tika.
