new purpose getting function.
Update the ca-cert.pem and pca-cert.pem "CA" certificates so they
really are CA certificate: that is they have the appropriate extensions.
yet.
Add a function X509_STORE_CTX_purpose_inherit() which implements the logic
of "inheriting" purpose and trust from a parent structure and using a default:
this will be used in the SSL code and possibly future S/MIME.
Partial documentation of the 'verify' utility. Still need to document how all
the extension checking works and the various error messages.
Extend the X509_PURPOSE structure to include shortnames for purposed and default
trust ids.
Still need some extendable trust checking code and integration with the SSL and
S/MIME code.
