Moved from external 'notify-send' command to using notify2 library

This probably fixes https://github.com/rinaldus/mail-notifier/issues/6

README.md

@@ -12,9 +12,14 @@ This is Light weight mail notifier written in PyQt5. It checks your mailbox peri
 ![MailboxFull](https://raw.github.com/rinaldus/mail-notifier/master/screenshots/screen2.jpg)
 ![Settings](https://raw.github.com/rinaldus/mail-notifier/master/screenshots/screen3.jpg)
 
+## System requirements
+ - Python 3
+ - PyQt5
+ - *(after version 3.01)* [notify2](https://pypi.python.org/pypi/notify2) library
+
 ## Install
 
-You need to install PyQt5 as dependency. Then just clone this git repository or download release and copy all files where you want to store this program. No additional installation is required.  
+Just clone this git repository or download release and copy all files where you want to store this program. No additional installation is required.  
 *In version 0.10 you also need to edit mail-notifier.py and fill your mailbox credentials in 70-72 rows*
 
 ## Launch

mail-notifier.py

@@ -18,11 +18,13 @@ from PyQt5 import QtCore, QtGui, QtWidgets
 import os
 import socket
 import time
+import notify2
 from datetime import datetime, date, time
 
 #variables
 programTitle = "Mail Notifier"
-programVersion = "3.01"
+programVersion = "3.01-dev"
+notify2.init(programTitle)
 settings = QSettings(os.path.expanduser("~")+"/.config/mail-notifier/settings.conf", QSettings.NativeFormat)
 def GlobalSettingsExist():
     if ((settings.contains("CheckInterval") and settings.value("CheckInterval") != "") and
@@ -439,7 +441,8 @@ def mail_check():
     window.lastCheckCount = mail_count
 def notify(message):
     if settings.value("Notify"):
-        subprocess.Popen(['notify-send', programTitle, message])
+        n = notify2.Notification(programTitle, message)
+        n.show()
     return