Fix for issue #263 and avoiding unneeded popups

[haneefdm]

1. New feature
   • A performance improvement has been made at startup. It was taking 2-3 seconds to parse the symbols out of the elf file. It is now cut in half and the results are cached. When cached results are used, it takes a few milliseconds.
2. Issues fixed
   • Fixed Issue #263. Static functions were not properly detected because of the differences in how gdb and objdump reported pathnames. It made things like step/next to not work. Much thanks to @Lykkeberg and @stalyatech for reporting and testing solutions
   • When using multiple processors, TCP ports should be allocated consecutively, remote chance of failures avoided
   • serialport binary module updated for latest Node.js/Electron
   • Watch and hovers caused too many popups. Something changed in VSCode. These are now suppressed. There were also popus when setting a breakpoint while program was running and single stepping too fast and these are now suppressed.
   • When runToMain was enabled, it caused a popup to appear for a failed stack trace. Again something changed in VSCode where it is requesting stack traces when program is not stopped.