LeapHttpClient verifies hostname.

This fixes #3287
Backstack OK from notification bar.

Pressing back after entering Dashboard from notification bar, the user
goes back to home.
Retains username if login process failed.

New login dialog shows the original username, so that if the user failed
writing his/her password, s/he does not have to write again the
username.
ProviderAPI intent receives actions and parameters.

We no longer use BundleExtras named as the action ProviderAPI is
intended to perform, but we standardise this name
(ProviderAPI.PARAMETERS), and use setAction to pass that action string.
Merge branch 'hotfix/disabled-hostname-verifier' into develop
Merge branch 'bug/backstack-screwed-up-by-notification-tap' into develop
FileNotFoundException catched in all downloads.

Added a new catch block in all downloads methods.
EIP fragment is replaced if provider is switched.

We were checking if eip existed before adding it again, but that check
can be removed if we make a replace instead of an add.
Merge branch 'feature/providerApi-actions-instead-of-bundleExtras' into develop
Merge branch 'feature/retry-login-retain-username' into develop
Merge branch 'bug/provider-down-not-differentiated-from-certificate-error' into develop
Merge branch 'bug/eip-fragment-is-not-showed-after-switching-provider' into develop
Disallow export of EIP service Intents
Use java.security classes to validate string certificates and keys from provider
Assets providers have danger_on "false".
Merge branch 'bug/eip-service-exported-with-no-access-control' into develop
Merge branch 'bug/lack-of-input-validation-on-user-certificates' into develop
Merge branch 'hotfix/danger_on-is-true-for-assets-provider' into develop
Renamed certificate handling methods.

I still let one method to bypass hostname verifier, otherwise dev.bm
will not work.

I've reduced downloading functions to 3: download without CA, download
with commercial CA and download with provider CA.

I only download CA cert once, when the user selects the corresponding
provider. Each time a user switch provider, the cert is downloaded
(along with other json files).
Removed cookie to logout chain.