Git Bash: Set the HOME environment variable if unset

By setting if already here it gets picked up by upstream MSYS's
/etc/profile. Also, setting it dynamically instead of at installation time
solves the problem when users are running an installation done by an
admin, see [1] for details.

[1] https://github.com/msysgit/git/issues/119

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Git Bash: Reorder code a bit to clarify the workflow

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Rename START_DIR to the more approproate LOGIN_DIR

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Git Bash: Add a fallback to USERPROFILE for HOME

This is also what we do for msysgit.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
readme: Do not mention the OpenSSH HPN patches anymore

Currently, our version of OpenSSH does not use the HPN patches anymore as
they were causing Git to hang in the "Resolving deltas" step when fetching
over SSH.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
profile.d: Reorder the sections in defaults.sh a bit

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
profile.d: Enable Git completion and define a Git prompt, if supported

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
profile.d: Use "." instead of "source" for its shortness

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Add msys-libiconv, msys-libexpat and msys-mktemp as required package

msys-libxml requires msys-libiconv
msys-xmlto  requires mktemp
msys-python requires msys-libexpat

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>