multiple fixes

[gdbarron]

• issue Find-TppCertificate does not appear to support "offset" #92, add offset parameter to Find-TppCertificate
• fix issue Include Private Key in Base64 PKCS #8 #95, allow inclusion of private key for format Base64 (PKCS Add Search-TppCertificate #8) in Get-TppCertificate. Earlier versions of Venafi documentation listed this incorrectly, but has been resolved.
• fix issue Params hash table in Get-TppCertificate #96, Get-TppCertificate failing when pipilining due to adding a key to a hashtable that already exists
• fix issue Creating Application and pushing to vaut #97, linux style paths which use / instead of \ were failing path check due to invalid regex