liq| er|: put ei_connection() just before ei_render().
liq| log|: trace.openFile():
m_logfile.open(name, trunc)  -->  m_logfile.open(name)
liq| log|: LogMgr::open(name) --> LogMgr::open(name, mod)
liq| er|: add ipr to ER - 8. put iprBegin() before prologue()
liq|: renderermgr, add assert(m_renderer)
liq| er|: add ipr to ER - 9.  liqIPRNodeMessage -isrunning
liq| er|: add ipr to ER - 10. +liqGlobalVariable::iprRendering
- +liqGlobalVariable::iprRendering for "liquid -ipr"
- liquidmayaStartIprRender() calls IPRRenderBegin();
- liquidmayaStartIprRender() calls "liquid -ipr" which calls IPRDoIt();
- liquidmayaStopIprRender() calls IPRRenderEnd();

TODO:
refactoring