In commit 53796fc4, bitbake fails at parsing. It slipped through,
as I did not invoke any testing before submitting 53796fc4. This
commit resolves the obvious shortcoming.

The description is not indented after line breaks. All other
information, i.e., the dependencies and SRCURI, are indented with
four spaces after line breaks. Shell scripts are indented with
multiples of four spaces.

In recipes-ros, I located and checked for tabulators and spacing
with these bash commands:

egrep '^ [^ ]+' . --exclude *.patch -R
egrep '^  [^ ]+' . --exclude *.patch -R
egrep '^   [^ ]+' . --exclude *.patch -R
egrep '^    [ ]+[^ ]+' . --exclude *.patch -R

While going through the recipes and manually improving the layout,
I also adjusted the descriptions to use maximal 100 characters
per line.

Besides updating ros-comm, this commit removes the second hash
values, that probably slipped-in during the last update.

The ros-comm 1.9.53 now also contains the new package rosbag-storage.

The ros-comm recipes are updated to 1.9.50 to be in line with
https://github.com/ros/rosdistro/blob/ef3a7449d7f7ef6e691a5724ef6c485e75cfd4af/hydro/release.yaml.

The ros-comm recipes are updated to 1.9.48 to be in line with
https://github.com/ros/rosdistro/blob/4551e7c32d1b34984410b79bc0ec36afe3d3d245/hydro/release.yaml.
The previously applied patches have been included in 1.9.48 and are
removed from the recipe and this repository.

Signed-off-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>

As the license text of the xmlrpcpp changed, the license checksum
is adjusted.

When importing the rosbag python module, it requires these python modules.