B3j0f.middleware

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- fix the function getmcallers at initialization of the first iteration of found middlewares.

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- fix build error.

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- remove the function 'core.get'.
- add the function 'core.getmcallers' in order to get all middleware callers bound to input protocols.
- ensure resolution of successive protocols inside an url scheme with the separator '+'.
- ensure resolution of multiple protocols inside an url scheme with the separator '-'.
- add the parameter 'cache' in the function 'url.fromurl'.

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- library creation.