ibrcommon: Replace "+=" syntax for variables
Add gcov and debug option to configuration.ac files

Support for code coverage using clang is excluded for now.
Add coveralls support to Travis CI control file
Add code coverage files to .gitignore
Merge pull request #38 from ejonny/travis-gcov

Automatic measuring of code coverage
ibrdtn: Set initial absolute sequence number to a random value
Merge pull request #39 from ejonny/random-seqnr

ibrdtn: Set initial absolute sequence number to a random value
ibrdtn: Use static calls to generate random numbers and patterns
daemon: Use static pattern to access methods of Random class