Add support of base64 encoded content

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Mention base64 encoding for files API

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add files encoding support on context level

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Accept encoding attribute in files API

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add base64 encoding selector to new file UI so you can add image to repo

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Move all Context classes into Services

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix encoding pass to edit file satellite

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Replace context with service in specs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Replace context with service in lib

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix require for file services

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'feature/base64_content' into 'master'

Feature: base64 encoding for blob content
 Merge branch 'refactoring/context_into_services' into 'master'

Refactoring context Into services

To prevent confusion where to write logic. Context or Service?
Explain allow_username_or_email_login LDAP setting
 Merge branch 'explain_allow_username_or_email_login' into 'master'

Explain allow_username_or_email_login LDAP setting
remove deprecated_finders