put note explaining why we're not caching system boot time
put note explaining why we're not caching system boot time

creativewild/psutil,end18/psutil,stupidcache/psutil,google-code-export/psutil,huson2012/psutil,jucapj/psutil,google-code-export/psutil,nmani1905/psutil,nmani1905/psutil,huson2012/psutil,AlanZatarain/psutil,vmolsa/psutil,stupidcache/psutil,shiva21/psutil,tigerneil/psutil,skyshe/psutil,Alwnikrotikz/psutil,kiranvizru/psutil,zhengzheng/psutil,djhaskin987/psutil,tigerneil/psutil,kiranvizru/psutil,skyshe/psutil,anfedorov/psutil,google-code-export/psutil,chjwang/psutil,end18/psutil,vmolsa/psutil,stupidcache/psutil,peter-hst/psutil,vmolsa/psutil,marmolu/psutil,skyshe/psutil,end18/psutil,PFZheng/psutil,djhaskin987/psutil,PFZheng/psutil,creativewild/psutil,creativewild/psutil,Alwnikrotikz/psutil,kiranvizru/psutil,shiva21/psutil,peter-hst/psutil,tigerneil/psutil,tigerneil/psutil,skyshe/psutil,anfedorov/psutil,google-code-export/psutil,huson2012/psutil,jucapj/psutil,djhaskin987/psutil,chjwang/psutil,djhaskin987/psutil,marmolu/psutil,kiranvizru/psutil,end18/psutil,AlanZatarain/psutil,zhengzheng/psutil,vmolsa/psutil