ref #1460 [Missing and incomplete frames on the wire ]

http://redmine.named-data.net/issues/1460
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Most incomplete frames cases fall to key frames fetching. As the
interest lifetime for key frames is always set constant and big (equals
to maximum specified in the parameters), there is no retransmission
strategy for key frames - key interests timeouts could not be
triggered.
There is a need to prevent this and provide some retransmission
strategy for key frames.
One of the possible solutions:
1. Before expressing interests for the next keyframe, note recent GOP
interval - this value should give an estimate of how frequently key
frames are generated.
2. Set key interests' lifetime to be "GOP_estimate-Buffer_size", where
Buffer_size - current buffer size (in  milliseconds). This adjustment
will allow timeout timer triggering before frame should be played out,
but already after it has been produced (actually, timer will fire
somewhere during "assembling period" of a key frame).

adjustments for this commit:
- use GOP value provided by config file for determining key frame
interests' lifetimes
- added GOP parameter to the config file
ref #1104 [Recover fetching data after network is down]

http://redmine.named-data.net/issues/1104
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- added "reset" methods for pipeliner, consumer, chase-estimation
- added states for pipeliner and consumer. consumer can be in one of
these states: Inactive, Chasing, Fetching. pipeliner can be in one
these states: Inactive, Chasing, Buffering, Fetching.
- fixed code for refining extra pending interests in slot data
structures (needed for cases, when pre-fetching caused issuing larger
amount of interests than frame really has)
- added code for FrameParityData class to init from the frame (RS28
encoding is hidden in this abstraction)
- implemented rebuffing logic in pipeliner - if there is no activity
(new data) for more than MaxInterruptionDelay, rebuffing occurs
- fixed typos
'issues/1104-recovery' -> 'dev'