1.60: Many bug-fixes (2023)

• Allow to use a datetime.timedelta parameter for Client.set (PR from Theo Massard)
• Fix cmemcahe_hash 0 values being translated to 1 (PR from Chow Loong Jin)
• Fix tuple key support in multi methods (PR from Sergii Mikhtoniuk) #154
• Add support for default value in get (PR from Jakub Szafrański)
• test_memcache.py: try import unittest.mock (PR from Tim Orling)
• Use == as suggested by Python 3.8 (PR from @za)
• Decoding in slab funcs, replacing "1" with "True" in while. #175
• Tell PyPI to parse README as markdown (PR from @MartinThoma) #168
• test_memcache.py: try import unittest.mock (PR from @moto-timo) #172
• Removed Python 2.7 from setup.cfg, adding 3.8-3.12
• Add support for default value in get() (PR from @samupl) #158
• Fix tuple key support in multi methods (regression in 1.55). (PR from @sergiimk) #155
• Fix cmemcahe_hash 0 values being translated to 1. For example "ob" would hash to 0 and then get converted to 1. Looks like this dated back to 2009, the original code we imported for that hash function. (PR from @hyperair) #152
• Removing six.PY2/3 conditionals
• Removing "time" from delete and making expiry mandatory in touch. (port of @erankor's PR in #30 )
• Added quit() method. This method sends the 'quit' command to the servers and then closes the connections, reducing the number of TIME_WAIT sockets hanging around the OS. (PR from @userrl) #15
• Allow to use a datetime.timedelta parameter for Client.set (PR from @tbobm) #146
• Allow keys to be encoded before use. (Port of PR in #52 from @harlowja)
• Removing historic python 2to3 code and deprecated socket.error (for OSError). (PR from @pgajdos) #186
• Updating to the latest PSF license