MISC: Improve several things relating to PID lookups (#1594)

findRunningScriptByPid needlessly took a "server" argument. This caused
there to be a "getRunningScriptByPid" version that did *not*, and it was
looping through all servers in order to function, which is needlessly
inefficient.

By removing the parameter and the needless inefficient helper method,
the following changes:
- Many Netscript functions such as isRunning() and getScript() become faster.
- The terminal "tail" command now works by pid regardless of the current
  server. Note that "kill" already worked this way.

I also improved the docs around "tail", since the pid argument wasn't
in the help.

src/Terminal/HelpText.ts

@@ -32,14 +32,14 @@ export const TerminalHelpText: string[] = [
   "    mv [src] [dest]                  Move/rename a text or script file",
   "    nano [files...]                  Text editor - Open up and edit one or more scripts or text files",
   "    ps                               Display all scripts that are currently running",
-  "    rm [OPTIONS]... [FILE]...	      Delete a file from the server",
+  "    rm [OPTIONS]... [FILE]...        Delete a file from the server",
   "    run [script] [-t n] [--tail]     Execute a program or script",
   "        [--ram-override n] [args...]",
   "    scan                             Prints all immediately-available network connections",
   "    scan-analyze [d] [-a]            Prints info for all servers up to d nodes away",
   "    scp [files...] [server]          Copies a file to a destination server",
   "    sudov                            Shows whether you have root access on this computer",
-  "    tail [script] [args...]          Displays dynamic logs for the specified script",
+  "    tail [script/pid] [args...]      Displays dynamic logs for the specified script",
   "    top                              Displays all running scripts and their RAM usage",
   "    unalias [alias name]             Deletes the specified alias",
   "    vim [files...]                   Text editor - Open up and edit one or more scripts or text files in vim mode",