Merge pull request #22 from hintjens/master

Send/receive files (KISS)
Problem: Uses old API for zyre_new
Solution: Update invocation of zyre_new
Problem: Configure test for zyre just tests czmq
Solution: Actually test zyre
Merge pull request #24 from jemc/configure_zyre

Problem: Configure test for zyre just tests czmq
Merge pull request #25 from jemc/zyre_update

Problem: Uses old API for zyre_new
Problem: Android needs to provide special LDFLAGS to libtool linking
Solution: Accommodate the LIBTOOL_EXTRA_LDFLAGS env var
Merge pull request #26 from jemc/master

Problem: Android needs to provide special LDFLAGS to libtool linking
Problem: wasting time with clunky use of CZMQ project scripts

Solution: switch to zproject (yay!)