Support Python 3.14 (#97)

• add to CI
• _pty_size(): fix TIOCGWINSZ struct now that fcntl.ioctl() is strict about buffer size

• fix key_from_env() to detect available key types (fixes compatibility with paramiko-4.x which removes DSS key support) #93 #95
• test-matrix updates #92 #94

• Fix --parallel option on macOS with Python-3.8 or later by always using multiprocessing "fork" mode (probably also needed on Linux with Python-3.14 or later) #88
• Require Python-3.5 or later (finally drop support for Python-2.7), and clean-up old support code: #56 #85 #87 f00a679

• #62 optimize _endswith()
• #64 remove remnants of python-2.5 support, simplify paramiko import
• #67 fix rsync_project() exclude arg for python-3
• #77 improve retry logic which checks for "Error reading protocol banner"
• #74 fix pipe fd leak from parallel mode task processes

• #59 fix compatibility with Python 3.10
• #60 fix local() handling of failing commands with capture=False (broken in 1.19.0 by #54)

• #61 fix compatibility with Python 3.10

• #47 add encoding kwarg to local() (relevant for python3)
• #54 fabric/fabric#2155 fix error() output for local(... capture=True)
• #52 fabric/fabric#1099 add space around hostname in disconnect message
• #53 #55 test matrix and docs build updates

• #50 fix regression of pty behavior for run() and sudo(), introduced in 1.17.0 along with stdin feature
• #49 switch CI setup to GitHub Actions, for the 1.17 branch

• #48 fix regression of pty behavior for run() and sudo(), introduced in 1.17.0 along with stdin feature
• #40 #42 update test matrix, update some tests for updated paramiko/cryptography

• #36 more robust default temp_dir for put() and get() with use_sudo=True
• #31 enable switching install_requires back to "paramiko" with PARAMIKO_REPLACE=1
• #38 fab --version now distinguishes between paramiko-ng and upstream Paramiko
• #30 print specific unrecognized SSHException, instead of just showing password prompt
• #33 small cleanup of fabfile import, parallel task wrapper function
• #35 #37 switch from Travis-CI to GitHub Actions for CI
• docs links updates, tiny wording updates