Enable to use odd filenames

[delphinus]

1. 75ce5c5 Fix errors in creating notes including $ in filenames.

   # master build
   > nb create --filename 'foo$bar$.md'
   /usr/local/bin/nb: line 1263: bar: unbound variable

2. eabc1b1 Enable to get IDs even when filenames have [ * chars.

   > nb add --filename '[foo].md'
   > nb add --filename '*foo*.md'
   
   # master build
   > nb list
   # prints no line
   
   # this PR
   > ./nb list
   [2] *foo*
   [1] [foo]

[delphinus]

For performance issue, we should use bash parameter expansion for replacing [ * in patterns, maybe.

escaped="${__basename:-}"
escaped=${escaped//\[/\\[}
escaped=${escaped//\*/\\*}
# now escaped completely

But this seems redundant for me. So I used sed to replace. Which do you prefer?

escaped=$(printf "%s" "${__basename:-}" | sed -e 's/[\[\*]/\\&/g')

[xwmx]

Thanks! I'll check it out.

Parameter expansion is usually faster since it doesn't create a subshell and call sed. I've had to replace printf and sed with bash-specific solutions in a few places like _get_title() because it's more performant. Command substitution is one of the things that appears to be slowing down list.

I do a lot of benchmarking with time and, more recently, hyperfine, so we should determine the performance impact of each approach. I've been trying to pare the list loop down and optimize _index get_id to identify and isolate the bottlenecks.