tstools: new package

[Thomas: properly indent help text, add largefile dependency, remove
unneeded libpcap dependency, remove unneeded CLEAN_CMDS, reorder build
and install commands, remove uneeded <pkg>_INSTALL_STAGING,
<pkg>_INSTALL_TARGET and <pkg>_INSTALL_IMAGES variables, move from
package/multimedia/ to package/, add license details, rename patch to
remove version number in the patch filename.]

Signed-off-by: Tzu-Jung Lee <tjlee@ambarella.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>