update README to 7.0.4
refs Tokutek/ft-engine#30 trace all txn begin calls
refs #71 rearrange IS code
refs #71 basic lock tree visualization
refs #83 cond compile gdb on error feature
refs #82 delete the user data information schemas
added -flto -fuse-linker-plugin to RelWithDebInfo #77
Merge branch 'lto' of github.com:Tokutek/ft-engine into lto