Allow all parameters in the cache config, and override them in specific usages

[jcugat]

When setting the cache config, I'd like to set there default values (for TTL and namespace for example):

caches.set_config({
    'default': {
        'cache': "aiocache.SimpleMemoryCache",
        'namespace': 'my_namespace',
        'ttl': 60,
    },
})

From that point, all the usages of the default cache would use the namespace and ttl set, unless passed explicitly in decorators and calls:

@cached(alias='default')
async def something_cached(self):
    # This would cache with the default parameters defined in the config
    return await do_stuff()

@cached(alias='default', namespace='another_namespace', ttl=3600)
async def something_else_cached(self):
    # This would cache with the parameters defined in the decorator instead of the config
    return await do_stuff()

# Same for these
caches.get('default').get('foo', default=False, namespace='bar_namespace')
caches.get('default').set('foo', True, namespace='bar_namespace', ttl=86400)

[argaen]

There are two things here.

On one hand is the part of specifying all the parameters through config. This is already possible except for TTL but because there is no instance attribute for attribute, its just per function. If you want this, we could add ttl in the class constructor too.

On the other hand is the part of overriding with the specifics you pass in the decorator. I guess we could do that in https://github.com/argaen/aiocache/blob/master/aiocache/decorators.py#L59, if there is alias load the config and then create new cache with the new args if passed.

[shizidushu]

I use cachedRedis = functools.partial(cached, ttl=60, alias='default'), it seems working.