improve brief descriptions #336

Job	Run time
Linux_options (aec_off png_off jasper_off openjpeg_off, -DUSE_AEC=OFF -DUSE_PNG=OFF -DUSE_Jasper=...	48s
Linux_options (aec_on png_off jasper_off openjpeg_off, -DUSE_AEC=ON -DUSE_PNG=OFF -DUSE_Jasper=OF...	47s
Linux_options (aec_off png_on jasper_off openjpeg_off, -DUSE_AEC=OFF -DUSE_PNG=ON -DUSE_Jasper=O...	50s
Linux_options (aec_off png_off jasper_on openjpeg_off, -DUSE_AEC=OFF -DUSE_PNG=OFF -DUSE_Jasper=O...	51s
Linux_options (aec_off png_on jasper_on openjpeg_off, -DUSE_AEC=OFF -DUSE_PNG=ON -DUSE_Jasper=ON...	50s
Linux_options (aec_on png_on jasper_on openjpeg_off, -DUSE_AEC=ON -DUSE_PNG=ON -DUSE_Jasper=ON ...	48s
Linux_options (aec_off png_off jasper_off openjpeg_on, -DUSE_AEC=OFF -DUSE_PNG=OFF -DUSE_Jasper=O...	52s
Linux_options (aec_on png_off jasper_off openjpeg_on, -DUSE_AEC=ON -DUSE_PNG=OFF -DUSE_Jasper=OFF...	51s
Linux_options (aec_off png_on jasper_off openjpeg_on, -DUSE_AEC=OFF -DUSE_PNG=ON -DUSE_Jasper=OF...	52s
Linux_options (aec_on png_on jasper_off openjpeg_on, -DUSE_AEC=ON -DUSE_PNG=ON -DUSE_Jasper=OFF ...	52s
Linux_options (aec_off png_off jasper_off openjpeg_on, -DUSE_AEC=OFF -DUSE_PNG=OFF -DUSE_Jasper=O...	48s
Linux_options (aec_on png_on jasper_off openjpeg_on, -DUSE_AEC=ON -DUSE_PNG=ON -DUSE_Jasper=OFF ...	46s
Linux_options (g2c, -DBUILD_G2C=ON -DPTHREADS=OFF -DLOGGING=ON -DJasper_ROOT=~/Jasper)	1m 6s
Linux_options (g2c_pthreads, -DBUILD_G2C=ON -DPTHREADS=ON -DLOGGING=ON -DJasper_ROOT=~/Jasper)	1m 8s
Linux_options (shared, -DBUILD_SHARED_LIBS=ON)	56s
	13m 5s

Provide feedback