.NET 3.5 Compatibility

As described here:
https://github.com/jaymedavis/stripe.net/issues/26#issuecomment-6225018
Full support for 3.5 compatible nuget build

Should allow complete 3.5 support for Stripe.net's Nuget.
Removing binaries / modifying gitignore

Accidentally missed these binaries not being ignored initially...
removed.
Defining NET40

Forgot to define NET40 in the primary csproj. Fixed.
Merge pull request #1 from jaymedavis/master

Latest from jaymedavis/stripe.net
Merge pull request #2 from iATN/master

Latest from jaymedavis/stripe.net
Integrating StripeBankAccount.cs into .NET 3.5 project
Exposed Currency property on StripeCustomer
added receipt_email to StripeChargeCreateOptions, bumped version
added some missing properties to StripeCard
Merge branch 'master' of https://github.com/jamesfoster/stripe.net
cleaned up property order to match docs
cleaned up property order and added StripeDiscount to StripeSubscription
added some missing properties to StripeDispute (more to do here)
added missing properties to StripeInvoice
bumping version
added StripeListOptions inheritance to StripeEventListOptions
made StripeSubscriptionService access StripeSubscriptionCreateOptions as an optional parameter
bumped version
Add JsonIgnore attribute to properties that are *hijacked* through *Internal properties.
fixes #233
little cleanup from the camel case contract resolver
cleaned up merging for 3.5 support and bumped version