* Added new guide on CorDapp Constraints Migration procedures.
* Apply formatting and upper/lowercase changes.
* Updated following PR review feedback from RGB and MH.
* Minor clarification and cleanup.
* Clarify step to ensure there is only one version ("signed") of the same Contracts CorDapp in the nodes /cordapp folder
* Incorporating feedback from SS.
* Replaced "propagate" with "transition".
Adjust terminology to be consistent.
* Removed confusing statement.
* Document CorDapp upgradeability guarantees.
* Incorporating feedback from RGB.
* Incorporating feedback from MH.
* Minor updates following re-review by RGB
* Updates following review by MH.
* Include new document in index.
* Incorporating review feedback from MH.
* Instructions on how to perform H2 DB upgrades without starting the node.
* Formatting error. Adds required subsections in H2 docs.
* Merges duplicated information about H2 DB access.
* Drops script references for now.
* Clarifies upgrade notes.
* Better title.
* Inr
* Addresses review comments.
* Addresses review comments.
* CORDA-986 and CORDA-985 CompositeKey and Signature verification performance fixes (#2467)
* CORDA-696: Create separate transaction types for contract upgrade transactions.
Add rationale around upgrade transactions
Move contract upgrade transaction resolution logic into internal until it's stabilised.
Throw a better exception when contract attachment not found
Default legacy contract constraint to always accepting - needs to be changed to whitelist constraint before merging
Introduce a new upgraded contract interface that allows specifying the legacy constraint.
Remove StateLoader, make all tx resolution functions take in ServicesForResolution
Contract upgrade transactions can handle whitelist by zone constraints
When creating a contract upgrade transaction, make sure the attachment of the old cordapp gets attached when using hash constraints.
Attachment lookup for a given contract class name only scans currently loaded cordapps, and we don't load old versions of cordapps.
CORDA-696: Update upgrade docs
