v0.15: Version 0.15

Changelog:

dce7644 network: Add workaround for Microsoft Windows Subsystem for Linux
70d1c2a examples/dummy-iiostream: Fix instructions
0892972 local: Fix low-speed mode
fa6ec67 appveyor.yml: Add workaround for 32-bit build
956bbc5 appveyor.yml: Fix libzip dll name pattern
c9909f2 Fix buffer/device mixup in docs
7dddeec Prevent out-of-bounds access in read_each_attr()/iio_channel_attr_read_all()
8ac1893 tests/iio_writedev: Add iio_writedev analogous to iio_readdev
ac8debc iio_adi_xflow_check: Avoid accessing device after context destruction
fa82974 Install iiod upstart conf file
61322cb Install iiod SysVinit script
e688c76 Install iiod.service file
185128c Fix typo in CMakeLists.txt
c8d5306 iio_readdev: Fix getopt() handling
52a5f07 iio_info: Fix getopt() handling
19d642c iio_genxml: Fix getopt() handling
faa6341 iio_attr: Fix getopt() handling
989db5e iio_adi_xflow_check: Fix getopt() handling
f5d8ddc appveyor.yml: Drop the initial core update which updates the package list and upgrades all the outdated packages. The conflicts are not handled properly when using the --noconfirm option(default values).
227e067 CMakeLists.txt: Fill in the Windows file information (version, name, copyright, year).
854471e appveyor.yml: Install windres for reading Windows resource files (.rc)
7d29b98 Added a new variable to iio.Buffer stored in self._ctx, this is reference to a Context variable. This reference ensures that the Context outlives the buffer, if this is not the case a segmentation violation will occur when destroying the buffer.