Support Anaconda 2019.03

Fix 2.4 builds: redeclaration of posix_close

Ported from https://bugs.python.org/issue20594

macOS: prefer homebrew openssl 1.1.x over 1.0.x, see #839

closes #1316

closes #1314

Add pypy 7.1.0 portable builds

Add copy_python_gdb for 3.7.3 and move patches.

Fixes issue introduced in #1283 and #1308.

Add support for Python 3.7.3

Minor formatting changes

Add cpython 3.5.7

Adding a list to the notes of point #2 in Basic GitHub Checkout steps.

previously, it was not possibly to compile a python with homebrew
openssl 1.1 because the code always queried "openssl" and ignored
"openssl@1.1".

now, if 1.1 is installed, it is used to compile python and only
if it is not, 1.0 is checked and used.

Install python-gdb.py.

Add CI builds that actually build Python.

Force y, Y, yes or YES to confirm installation

For now this just builds the latest CPython, but it can be
extended to include other versions.

Skip with `[skip build]` in commit message.

The script in `Tools/gdb/libpython.py` has helper functions for
debugging Python processes under gdb. When installed to `{exe}-gdb.py`
it will automatically be loaded by gdb assuming it is in the safe path.

gdb resolves all symlinks, so having the single script is sufficient
regardless of how Python is invoked.

Since it is usually only included as part of a dbg/dev package, this
file is intentionally excluded from install by the CPython build
scripts. Like the packaging with EPEL/Debian, we opt to manually copy
it after the build/install.

To ensure this file gets picked up it is enough for users to put this in
their `~/.gdbinit`:

```
add-auto-load-safe-path ~/.pyenv
```

Fixes #1190.

Use xz compressed micropython 1.9.* tarballs

Add micropython 1.10

Add pypy3.6-7.0.0

Use explicit versions for CPython identifiers.

Fixes #1282.

Add pypy 7.0.0

Add a note for fish shell users (close #1203)

Add OPENSSL_NO_SSL3 patch for 3.3.7

Update ironpython development install location

Added new Anaconda 2018.12 installers.

new file:   plugins/python-build/share/python-build/anaconda2-2018.12
new file:   plugins/python-build/share/python-build/anaconda3-2018.12

Close #123

Add CPython 3.7.2 and CPython 3.6.8