Readable Log File for ReadCount Model

[EvaLiyt]

The log file should be readable when opened in Excel.

[kche309]

Add an option in LPhy for writing out all random variables with dimension > 1 as individual files.
https://github.com/LinguaPhylo/linguaPhylo

Variables that are a list or matrix should be written in their own log file with the "name of the variable" as the file prefix. Suggested format "variableName_sampleNumber.log"

Lists:
One line per element in variable log file.
For example a discrete variable x could have the log file x.log with

10
25
8
3

2D Matrix:
Each row as a new line, where columns are "comma" delimited.
For example, a variable x where there are two dimensions

2, 2, 3, 4
1, 1, 1, 2
3, 2, 2, 4

3D Matrix:
Same as 2D matrix, but each element is also a list with a "semicolon" delimiter.
For example, a read count matrix r with 2 cells and 3 sites, where each element is a list of nucleotide counts for A:C:G:T

10:2:0:0, 10:15:0:0, 0:1:2:8  
20:0:5:0, 18:3:0:1, 0:0:4:5 

Note: 4 Dimensions and beyond - each dimension will need their own delimiter. To be added when use case appears in the future.