consolidated most indra-specific constants in llcommon under indra_constants.h
fixed issues with operations on mixed unit types (implicit and explicit)
made LL_INFOS() style macros variadic in order to subsume other logging methods
such as ll_infos
added optional tag output to error recorders
cleaning up build
moved most includes of windows.h to llwin32headers.h to disable min/max macros, etc
streamlined Time class and consolidated functionality in BlockTimer class
llfasttimer is no longer included via llstring.h, so had to add it manually in several places
and reduce unnecessary dependencies and incredibuild wedging. Hopefully in
the long run this will reduce build time. Also cleaned up a lot of header
file usage to conform better to the coding standard.
reviewed by james and steve.