Document error and warning messages

[LHMarshall]

> simulation <- run.simulation(simulation)
Summary of warnings and errors:
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate 
scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 2) (occurred 1 time(s) in repetition(s):  3)

[LHMarshall]

> simulation <- run.simulation(simulation)
Summary of warnings and errors:
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 2) (occurred 4 time(s) in repetition(s):  1, 2, 3, 10)
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 4) (occurred 4 time(s) in repetition(s):  1, 2, 3, 10)
Error: No models could be fitted. (Model number: 3) (occurred 2 time(s) in repetition(s):  2, 10)
simpleWarning in ddf.ds(model = dsmodel, data, meta.data = meta.data, control = control, : Model fitting did not converge. Try different initial values or different model

 (Model number: 3) (occurred 2 time(s) in repetition(s):  2, 10)
-----

[LHMarshall]

Summary of warnings and errors:
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 2) (occurred 5 time(s) in repetition(s):  2, 3, 6, 9, 10)
Error: No models could be fitted. (Model number: 3) (occurred 1 time(s) in repetition(s):  2)
simpleWarning in ddf.ds(model = dsmodel, data, meta.data = meta.data, control = control, : Model fitting did not converge. Try different initial values or different model

 (Model number: 3) (occurred 1 time(s) in repetition(s):  2)
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 4) (occurred 2 time(s) in repetition(s):  2, 6)
Error: No models could be fitted. (Model number: 5) (occurred 2 time(s) in repetition(s):  2, 5)
simpleWarning in ddf.ds(model = dsmodel, data, meta.data = meta.data, control = control, : Model fitting did not converge. Try different initial values or different model

 (Model number: 5) (occurred 2 time(s) in repetition(s):  2, 5)
Error: No models could be fitted. (Model number: 6) (occurred 1 time(s) in repetition(s):  2)
simpleWarning in ddf.ds(model = dsmodel, data, meta.data = meta.data, control = control, : Model fitting did not converge. Try different initial values or different model

 (Model number: 6) (occurred 1 time(s) in repetition(s):  2)
simpleWarning in Distance::ds(data = dist.data, truncation = truncation, transect = transect, : Estimated hazard-rate scale parameter close to 0 (on log scale). Possible problem in data (e.g., spike near zero distance).
 (Model number: 6) (occurred 2 time(s) in repetition(s):  6, 9)

[LHMarshall]

Summary of warnings and errors:
simpleWarning in optimx.check(par, optcfg$ufn, optcfg$ugr, optcfg$uhess, lower, : Parameters or bounds appear to have different scalings.
  This can cause poor performance in optimization. 
  It is important for derivative free methods like BOBYQA, UOBYQA, NEWUOA.
 (Model number: 2) (occurred 2 time(s) in repetition(s):  76, 401)
simpleWarning in ddf.ds(model = dsmodel, data, meta.data = meta.data, control = control, : First partial hessian is singular; using second-partial hessian

 (Model number: 2) (occurred 1 time(s) in repetition(s):  127)