Hmm..it would seem that your last error notes that there are broken packages that are conflicting with your installation. Perhaps a way to correct the issue is by relying on aptitude to install the packages. Aptitude seems to work with narrowing down problems revolving around broken packages, so it may be of some help.

To install aptitude, use the following command sudo apt-get install aptitude and then try reinstalling your packages with sudo aptitude install ros-indigo-mavros ros-indigo-mavros-extras.

Additionally, I see that the dependencies libboost-filesystem1.54.0 and libboost-system1.54.0 are not able to be installed, so there may be an issue with those two making it not possible to install mavros and mavros extras because of those dependencies being needed to be used for both packages.

Edit: I just noticed you asked a similar question here ... did you try out the possible solutions posted there ?

Otherwise I think you could try to follow the instructions here: Mavros source Installation. At the end of that page there's also a skye blue box with additional information about raspberry pi.

Hope that helps :)