Like other TRICK_SYSTEM variables, users should not modify this.
This renders TRICK_LDFLAGS and TRICK_USER_LINK_LIBS redundant. While we
would like to eventually remove TRICK_USER_LINK_LIBS, it's not likely to
ever actually happen.
Refs #369
Adjusted all of the source code to point to the header files in their new
locations. Adjusted the makefiles for the header locations as well.
Added .gitignore files in the test directories to ignore test object code.