prepare for version 0.9-11
document issue with RDI files
typo correction in ?read.adp
working on bottom-tracking biosonic files

Test code:

    library(oce)
    source('~/src/R-kelley/oce/R/echosounder.R')
    source('~/src/R-kelley/oce/R/oce.R')
    source('~/src/R-kelley/oce/R/processingLog.R')
    d <- read.oce('03-BottomStructure.dt4', debug=dd)
    str(d)
    x11()
    plot(d)
    lines(d[['time']], -d[['range']]) # odd ... also, times wrong
working on echosounder bottom
read.echosounder(): prevent segfault caused by buffer overrun
echosounder: prepare for dual-beam and split-beam modes

Need more C coding.  And need to check on single-beam to ensure RLE
done right.  (It seems only zero-value runs are used.)
remove extra read
remove commented-out code
echosounder prelim work
summary(echosounder) indicates beamType
read.echosounder: add tests for split- and dual-beam

So far these are not handled well yet, though.
echosounder: test code for split- and dual-beam

This is not working correctly yet, and is being checked in mainly as a
placeholder.  Still, it can read and plot the following without
crashing (although I see runlength-encoding problems, and the bottom
trace is wonky): 01-Fish.dt4
02-AquaticPlants.dt4
03-BottomStructure.dt4
echosounder: start breaking up 4-byte chunks

(Incorrectly, still)
echosounder: decode some ping properties

In preparation for count-to-signal conversion
echosounder work (incomplete)

Now decoding quite a lot more of the header information, with the
eventual goal of converting amplitude from counts to dB.  This involves
a lot of cross checking in the docs and with the strings in the
biosonics 01-Fish.dt4 sample file.  My hope, as I work through the
manual, is to gather better understanding of how to decode the
profiles, which I think is wrong on run-length decoding and also
(perhaps) in something more major, given the mismatch to graphs
produced with biosonics software on some of the three sample files.  (I
still am perplexed by how the depth-time patterns can look so alike in
one sample file and unalike in another.)
new branch for tricky echosounder work
echosounder steppingstone: RLE early steps

Checking in mainly to thin out the diffs, which are large because of
going back on forth on the idea of handling all three cases in one
function.
echosounder: start renaming things in C code
echosounder seems OK on split-beam data

At least, it produces sensible-looking results on the 3 test datafiles
from biosonics.  NOTE: conversion to dB not done yet.  I'll get
single-beam working first.