1) writing the intro part of report
2) ploting bserror time varying Ncache and Chunck
Merge branch 'master' of https://github.com/francktcheng/BSERROR

Conflicts:
	doc/report/report.aux
	doc/report/report.log
	doc/report/report.pdf
	doc/report/report.tex
1) merge with cihui pan's writing