the startegy of FIFO has been done.
change the path of file
LRU strategy has been done.
增加makefile；修改注释
readme
add comments
new assignment3
new assign3_by yyx
relative all the previous 3 assigns
add a new function
delete the table.c
write some functions
add the function of create table,open table
finish several functions. but test failure
testInsertManyRecords has been passed
Merge branch 'master' into jerry

Conflicts:
	assign2/assign2.xcodeproj/project.xcworkspace/xcuserdata/xieyangyang.xcuserdatad/UserInterfaceState.xcuserstate
fisrt 4 functions has been done ^_^