Revert "Replace @VAR@ in Makefile.am files with $VAR"

This reverts commit d1ab00cab4d644d1048ed279f90e633b82cf4455.

Conflicts:
	tests/Makefile.am
syntax-check: skip sc_makefile_at_at_check
synchronize client and server in Test-proxied-https-auth.px
add ./configure valgrind support to test suites
fixing several memory leaks
added strlcpy(), concat_strings() rewritten

Signed-off-by: Tim Ruehsen <tim.ruehsen@gmx.de>
Add wrapper for using wget with a socks proxy.
content for commit 605d9053e50697c379e53188e906ef410849705f