fix osx serialport.list issue

currently the serial number is used in conjunction with /dev/cu.usbserial* (which i've never seen)

this patch uses part of the locationId string which matches the usual directory listing of /dev/{tty,cu}.usbmodem*
Update README.md with baudrate example
correct list under Unix when multiple devices of the same id are connected
Merge pull request #102 from rhasson/master

corrected list under Unix for multiple devices with the same ID
Merge pull request #100 from tmpvar/osx-list

fix osx serialport.list issue
Ticket: 104, reverting back.
Everything must occur after on('open')

I can't be the only one that made the newbie mistake of not registering a 
listener on open and ONLY when that is received start writing/listening for data. 

I can't see any mention of that in the main README.md so here's an update.
optimize osx serialport.list
native list approach for mac
fix the callback on list. callback was on the wrong function
package: remove "node-gyp" as a dependency

npm bundles its own internal copy of node-gyp,
so installing another copy is not necessary.
Merge pull request #114 from TooTallNate/patch-2

package: remove "node-gyp" as a dependency
Merge pull request #107 from Lophilo/doc

Everything must occur after on('open')
Fix package.json typo
Rewrite overlapped IO code to fix receiving data loss
Add new serial ports list method for Win32

New serial ports list method for Win32 allows enumerate some virtual COM
ports not listed in Device Manager
Merge pull request #120 from vkosar/master

Important fix in Win32 code
increase buffer size
Update src/serialport_unix.cpp to build on OpenBSD
Sleep for 1s before calling tcflush