Changed useless by-reference params to by-value
which forbids number literals (i.e. DT_*)

Added missing const keyword to std::string& parameter

Return back Makefile.in files. The intention is that configure/make pair will work without additional automake invocation

Fix the following two gcc warnings:

elfio/elfio_section.hpp:50:36: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
     const size_t get_stream_size() const
                                    ^
elfio/elfio_segment.hpp:99:23: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
     get_stream_size() const

Crash 7d695153fd8052529d480c2352d4ada33a44bada