Merge branch 'Parameter-File' into 'master'

Parameter file

First version of parameter file parser. Should be able to:
- Read integers
- Read floats
- Read doubles
- Read strings
- Ignore comments that start with '#'
- Validate that integers are not written as floats in the input file
- Check whether two values are present on the same line
- Print the contents of the structure that holds all parameters read from the file

I had to add `../src/parser.c` to the Makefile.am in the tests directory to get `make check` working. Not sure if this is the correct way of doing it.

See merge request !129