elfdep: Extract dependency information from ELF files

syntax: elfdep <pkgallpkg>

read filenames from stdin and ouputs dependency information on stdout

returns with exit status 1 on error
elfdep: Speed up dependency extraction

..by swapping inner and outer loops
elfdep: Fix multiple occurances of /aaa/../

This fixes /aaa/bbb/ccc/../../ddd to be converted to /aaa/ddd
elfdep: add canonicalized rpath to search path
elfdep: Add class/type and do self-provide only if type is DYN
elfdep: Fix empty rrpath because of failing readlink
elfdep: Add special pkg-internal dependencies to simulate LD_LIBRARY_PATH

We just assume that libraries that are included in the package are
on runtime accessible through some LD_LIBRARY_PATH setting wrappers
and so are not missing even if the binary has no rpath set.
elfdep: Cache readlink of rpath entries
repository: Update .gitignore