Replace newer tr command syntax with older ascii specific operations

[alangonzalez]

For busybox support, some commands don't support the newer syntax :alnum: :cntrl: etc options.

I replaced them with the older counterparts and in one case replaced upper->lower lower->upper with awk replacements.

Only issue I can see if we are allowing for LOCALE specific optimizations for using tr with the posix callbacks. I suspect we aren't since in the grep statement on line 71 we use the ASCII syntax of a-z.

So I believe this patch will preserve functionality for all platforms, but if there is concerns on still using :alnum: I can submit revised patch where I check if the tr command supports advanced functionality and then everytime the tr command is about to run put an if statement. I thought this would be klunky given how many uses of tr

The test for tr functionality is like this:

DATA=$(echo testing | tr -d '[:alnum:]')
if [ -n "${DATA}" ]; then
 # tr doesn't work
fi

[mboelen]

Thanks for your work on this. Looks good to me, so I have merged it.