Avoid closing the handle in mmap
Avoid closing the handle in mmap

Added mmap implementation for Windows. It uses MapViewOfFile similar to Bolt's implementation. MapViewOfFile  returns a pointer and not a byte array. Bolt changed their data structure to support it. 

Instead of changing the implementation of tsm data structure, I used a trick shown in https://groups.google.com/forum/#!topic/golang-nuts/g0nLwQI9www to use SliceHeader to convert the pointer into a slice.

Bolt's implementation also closes the file handle in mmap itself. It was resulting in a timeout, so implemented https://github.com/edsrzf/mmap-go/blob/master/mmap_windows.go logic to keep file handle open until munmap
Mindera/influxdb,mvadu/influxdb,arussellsaw/influxdb,runner-mei/influxdb,joaopedrotaveira/influxdb,joaopedrotaveira/influxdb,arussellsaw/influxdb,mark-rushakoff/influxdb,benbjohnson/influxdb,m4ce/influxdb,influxdata/influxdb,influxdb/influxdb,jipperinbham/influxdb,joaopedrotaveira/influxdb,joaopedrotaveira/influxdb,jgeiger/influxdb,m4ce/influxdb,jipperinbham/influxdb,linearb/influxdb,arussellsaw/influxdb,jgeiger/influxdb,mark-rushakoff/influxdb,jgeiger/influxdb,archsaber/influxdb,n1tr0g/influxdb,m4ce/influxdb,linearb/influxdb,daachi/influxdb,influxdb/influxdb,mnuessler/influxdb,jonseymour/influxdb,jipperinbham/influxdb,runner-mei/influxdb,benbjohnson/influxdb,daachi/influxdb,pkittenis/influxdb,Mindera/influxdb,n1tr0g/influxdb,mark-rushakoff/influxdb,pkittenis/influxdb,apigee/influxdb,otoolep/influxdb,jgeiger/influxdb,otoolep/influxdb,runner-mei/influxdb,chenziliang/influxdb,Mindera/influxdb,influxdata/influxdb,linearb/influxdb,pkittenis/influxdb,daachi/influxdb,otoolep/influxdb,otoolep/influxdb,Mindera/influxdb,daachi/influxdb,li-ang/influxdb,influxdb/influxdb,nooproblem/influxdb,li-ang/influxdb,mvadu/influxdb,jgeiger/influxdb,pkittenis/influxdb,jonseymour/influxdb,influxdb/influxdb,nooproblem/influxdb,joaopedrotaveira/influxdb,jgeiger/influxdb,vladlopes/influxdb,nooproblem/influxdb,mnuessler/influxdb,n1tr0g/influxdb,archsaber/influxdb,vladlopes/influxdb,n1tr0g/influxdb,mark-rushakoff/influxdb,linearb/influxdb,daachi/influxdb,mnuessler/influxdb,mnuessler/influxdb,apigee/influxdb,m4ce/influxdb,jonseymour/influxdb,nooproblem/influxdb,arussellsaw/influxdb,vladlopes/influxdb,jonseymour/influxdb,pkittenis/influxdb,apigee/influxdb,jipperinbham/influxdb,vladlopes/influxdb,m4ce/influxdb,nooproblem/influxdb,benbjohnson/influxdb,archsaber/influxdb,mvadu/influxdb,Mindera/influxdb,jonseymour/influxdb,mvadu/influxdb,influxdb/influxdb,chenziliang/influxdb,daachi/influxdb,otoolep/influxdb,apigee/influxdb,benbjohnson/influxdb,influxdb/influxdb,chenziliang/influxdb,jipperinbham/influxdb,runner-mei/influxdb,apigee/influxdb,n1tr0g/influxdb,archsaber/influxdb,jonseymour/influxdb,pkittenis/influxdb,arussellsaw/influxdb,mnuessler/influxdb,n1tr0g/influxdb,jipperinbham/influxdb,chenziliang/influxdb,linearb/influxdb,apigee/influxdb,mvadu/influxdb,mnuessler/influxdb,m4ce/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,otoolep/influxdb,arussellsaw/influxdb,mvadu/influxdb,Mindera/influxdb