revid/senders.go: increase pool maxAlloc for mtsSender

[Saxon Milton]

It was found that when using the mtsSender (which creates large MTS clips for writing) we were causing problems for the pool buffer. This was discovered to be related to the pool maxAlloc not being large enough for the writes. Therefore we should increase the allowable allocation using the poo.MaxAlloc function in the constructor for the mtsSender.

[Saxon Milton]

Merged in mts-buffer-max-alloc (pull request #486)

revid/senders.go: increase buffer pool maxAlloc in mtsSender

Resolves issue #382

Approved-by: Trek Hopton

→ <<cset 96e1be091046>>