stop failure to get commit id when in a git repository but not on
a tagged branch (fd 5 was non-existent).  Not tested with a tagged
branch.
add simple memory performance test
add memory write speed test.
add context switching speed test to "test memory" command.
allow setting of % of 252 byte RS protected packets that we want
to have delivered.  Adjust tests accordingly.  Create new test
for ~50% packet delivery on fakeradio in preparation for network
coding.
Fix fetch insert assertion
Fix printf format
Fix string buffer overflow
fixes and improvements to handling of git repo with no tags on branch.
minor tweaks to bash compatibility fixes.
Fix compiler warning
Merge branch 'meshextender' into 'development'
Fix version_string.sh: check for .git directory was too early
Fix Android compiler warnings ("%zd" and ssize_t)

Also squash some unconditional DEBUG statements
Fix printf formats
Remove stop file last during server shutdown to allow database cleanup
Fix output delimiter in "reverse lookup" command
Improve sendto(2) error log messages
Use ssize_t for sendto(2) return value, not int

Also improve error checking on ssize_t values (use ==-1 not <0) test
and cast ssize_t to size_t for comparisons
Improve sendto(2) failure diagnostics

In MDP client and server MDP overlay code