#73 Improve LTP retransmission limit computation

[Scott Burleigh]

The bug-0047-retransmission-limits fix cleaned up the difference between "reports" and "report segments" and made the computation of the limit on the number of reports for a given block dynamic, but two flaws have been identified.

1. The computation of segment loss rate (errors per segment) is incorrect. It should be 1.0 - ((1.0 - maxber) ** (maxSegmentSize * 8)).

2. The limit on the number of times any single report or checkpoint may be retransmitted should also be computed dynamically, as a function of segment loss rate, rather than hard-coded.

[Scott Burleigh]

Resolved 1 May 2015 in the ION 3.3.1 release.