Tom Peterka authored Aug 30, 2018 and Dmitriy Morozov committed Sep 04, 2018

Removed Master::IProxyWithLink and added optional iexchange argument to
Master::ProxyWithLink. The iexchange protocol now uses ProxyWithLink
with the optional iexchange argument. Removed e/simple/iexchange.cpp example
because it is superceded by e/simple/iexchange-particles.cpp. Change for() to
while() in e/simple/iexchange-particles.cpp and tests/iexchange.cpp. Changed
IProxyWithLink to ProxyWithLink in e/simple/iexchange-particles.cpp and
tests/iexchange.cpp.