edge.comp: eliminate false trigger upon startup

Fixing http://sourceforge.net/p/emc/bugs/346/

The edge component, edge.comp, starts with the last input value (last_in) 0, so
if you start the component, and the input is already 1, you will get a false
edge trigger.
added new configs for ppmc with encoder velocity estimation
pncconf -honour 7i43 address changes

priviously always used default address.
pncconf -fix off by one error on pin numbering of 5i25 boards
Changelog for 2.5.4
Release 2.5.4
tests: add some tests of the edge component
edge.comp: fix .out-invert pin on first invocation

Before this commit, edge.*.out and .out_invert would both be 0 after the
first invocation of the component's function.  This commit fixes
.out_invert to always be the inverse of .out.
edge.comp: fix output pulse width

The edge manpage claims that the output pulse width is controllable by
the .out_width_ns parameter, but there's a bug: the output pulse is one
thread period too long.

This commit fixes it.
Merge remote-tracking branch 'origin/v2.5_branch' into 2.6

Conflicts:
	VERSION
	debian/changelog
	src/hal/components/edge.comp
tests: add tests of the new "both" mode of edge.comp