Local AD check for Azure AD Synchronization

A simple script which checks the local server that Azure AD Connect runs on for the following:

* Time since successful synchronization with Azure AD
* Time since successful password synchronization with Azure AD
* Errors in event log indicating problems with synchronization

Parameters:
1: [Int] $allowedMinutesSinceSync (Default: 90): Time (in minutes) since last successful synchronization before a critical alert is raised.
2: [bool] $disableOutput (Default: $false): Toggles the status of $disableOutput and determines whether the script should generate any output.
3: [bool] $checkPasswordSync (Default: $true) Toggles whether password synchronization is synchronized between local AD and AAD.

The checks are performed using the following powershell commands:
* Get-ADSyncPartitionPasswordSyncState
* Get-ADSyncScheduler
* Get-WinEvent

The script has only been tested using NSClient++ on Windows 2016 servers and Nagios Core 4.4.5 and the check_nrpe command.