Fix scrolling in SWF.ListView.EnsureVisible(int index)

This fixes https://bugzilla.xamarin.com/show_bug.cgi?id=22483
[mdoc] New make test for the --dropns functionality
[mdoc] New make test, reproduces issue with --dropns when run with a secondary assembly that doesn't drop the specified namespace
[mdoc] added -dropns-assemblies parameter.
Will now only replace the namespace when the type or member is in a listed assembly
[mdoc] Formatting feedback from pull #1273
[mdoc] consolidated dropns and dropns-assemblies into a single parameter.

Based on pull request feedback, this is a simpler usage, and meets our required use-case. A sample version of this parameter would be: `--dropns MyUnifiedAssembly=MyDroppedPrefix`
[System] Add performanceCounters element to System.Diagnostics app.config configuration section

See http://msdn.microsoft.com/en-us/library/ms229387(v=vs.110).aspx for details about the element.
The value that is set by the element isn't currently used in Mono, but applications using it in their app.config crash otherwise (e.g. http://stackoverflow.com/questions/25741651).
Put KeyPairPersistence load into a try{}catch{} block.

Kpp.Load() will throw an unhandled exception if _filename (a folder to use as the key store) does not exist and it cannot be created.

This is an entirely valid thing to have happen - cert importing into the machine store (mozroots --import --machine --sync) as root will create a /usr/share/.mono/certs/ folder, but will not create /usr/share/.mono/keypairs - and since the root user owns /usr/share/.mono/, if the user tries to enumerate the certificates in /usr/share/.mono/certs/, they get 0 certificates returned due to the unhandled exception dropping each loaded certificate on the floor.

Closes: Xamarin bug 23015
Merge pull request #1273 from joelmartinez/docs-unified-fix

bugfix for mdoc update with --dropns feature
Merge pull request #1290 from directhex/master

Put KeyPairPersistence load into a try{}catch{} block.
Merge pull request #1287 from akoeplinger/fix-appconfig-performancecounters

[System] Add performanceCounters element to System.Diagnostics app.config configuration section
Merge pull request #1245 from StephenMcConnel/bug-22483

Fix scrolling in SWF.ListView.EnsureVisible(int index)
[sgen] Fix wbarrier use if we define SGEN_HEAVY_BINARY_PROTOCOL, HEAVY_STATISTICS or XDOMAIN_CHECKS_IN_WBARRIER
Add SqlCredential support -
- Tds.cs: Use SecureString objects for passwords; Add method to retrieve string from SecureString
- Tds42.cs: Use SecureString for passwords
- Tds50.cs: Use SecureString for passwords
- Tds70.cs: Use SecureString for passwords
- TdsConnectionParameters.cs: Use SecureString for passwords; Initialize Password parameter as cleared string; Add indicator for when password is set
- SqlConnection.cs: Use SecureString for passwords; Add SqlConnect method that accepts an SqlCredential along with the Connection string; Perform checking of parameters to ensure user/password not specified in connection string if credentials have been specified or using credentials when domain login is specified.
- SqlCredential.cs: Add new class with support for credentials
- System.Data.dll.sources: Add SqlCredential.cs to the build list
[System.Numerics] Fix unit test to succeed on different culture (XI runs tests them on several cultures)
Fix typo (and XI builds)
[runtime] Add wrappers around the wapi interrupt functions to mono-threads to reduce the amount of #ifdef WIN32 blocks in threads.c.
[runtime] Enable the new interrupt code on arm linux.
[runtime] Fix the unregistration of our exception handler on windows. Fixes #23221.
[runtime] Fix the windows build.