Make target to build parser source files.
With this one does not have to run 'make' to build
the whole C library, before building the R or the MSVC package.
It is enough to run 'make parsersources'.

Conflicts:
	Makefile.am
	src/Makefile.am
Fix maximal cliques R test case (#513).
Implement full graphlets in C, no projection yet (#513).
Graphlet projection in C (#513).
Redesigned graphlets API (#513).
Vectors of various types can now refer to each other.

I mean, a vector of a given type can have a function
that has an argument that is a vector of another type.
To achive this, I had to move the template type
definition to another file.
Add function igraph_vector_index_int.

Index a vector with an integer vector, in place.
Add function igraph_vector_ptr_index_int.

Index a pointer vector with an integer vector, in place.
igraph_graphlets now sort results.

According to decreasing Mu coefficients.
Fix an R test case for graphlets().
Free memory on error, in graphlets (#513).
Graphlets C docs (#513).
Graphlets R manual page (#513).
R: fix graphlets manual page errors (#513).
Merge branch '0.7-graphlets' into develop