Fix #228 introduced by variable length encoding where integer values stored on
single bytes in HBase were being cast to unsigned ints in
RowSeq.extractIntegerValue. Removed the bitmask and now single bytes are
returned correctly.

Signed-off-by: Chris Larsen <clarsen@euphoriaaudio.com>
fix check_tsd -c/-w options logic

it should fail only if both are None, not the other way around

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>
accept HTTP 202 as success

opentsdb v2 returns 202 when asked for datapoints

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>
Use `Cache-Control: max-age=0' instead of `no-cache'.

Varnish ignores `no-cache', and since `max-age=0' works just as well
for both Varnish and web browsers, and makes for simpler code, just
use that instead.