#1279 ccmanager ignores completion request

[pecan]

This is a request for comments.

ccmanager ignores completion requests when its length is the same as the previous mispelled request.
Example:
Create a virgin wx project. type "OnC", in the last method (OnAbout).
Completion will suggest OnClose. Hit escape.
Backup and change C to Q for OnQuit. No suggestions occur.
All three letter requests will be ignored until a 4th letter is typed.

This patch adds a test of the pattern text to determine if the last request is different from the current. It works for both plugins codecompletion and clangd_client.

[Miguel Gimenez]

I think this was fixed in [r12847].

[pecan]

Fixed r12847