An issue with computer less than 8 core

[TheBeautifulMoonlight]

Tanks for your code, I find the project cannot successfully compile on less than 8 core. On a 4-core CPU, the compilation of the srv files into .h files (such as SolveMTSP.h, ChunkStamps.h) could not be solved by recompiling. (Probably due to compiling order and parallel tasks). Anyone experiencing this problem can solve it by creating an empty header file or catkin_make it with other computer and use the .h file.