Added various library functions

Added to logger:
log(...) - will now include printing of nil values
table.tostring(t) - returns string representation of table values in Lua
syntax
table.tovstring(t) - returns vertical string representation of table
values in Lua syntax with
Amended table.print(t) and table.vprint(t) to handle nested tables

Added to stringhelper:
string.trim(str) - removes leading and trailing whitespace-like
characters
string.uc_first(str) - returns str with the first letter capitalized
string.capitalize(str) - returns str with the first letters of every
word capitalized
Fixed string.split(str, sep)
Fixed string.add(str, pos)
Amended string.split(str, sep, maxsplit) - takes optional third argument
for maximum resulting table length

Added to tablehelper:
table.extend(t, t_ext) - appends table t_ext to the end of t
table.arrmap(t, fn) - analogon to table.map for array tables, handles
enclosed nil values
Restricted exposure of meta table data