Remove gnu plot

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

On systems like Arch Linux `python` defaults to `python3` preventing
gitstats to start. This fixes it.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

[hoxu@users.sf.net: Debian Jessie and CentOS 6.5 have /usr/bin/python2,
but OS X Yosemite only has /usr/bin/python2.7. There does not seem to be
a portable way to refer to python 2.x, so unfortunately on some
platforms the shebang needs to be modified manually]

When generating HTML output with a custom stylesheet specified using
-c style='mystyle.css' the CSS file specified was not being copied to
the target directory.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Split limit 5 was off by one, which resulted in incorrect
processing of file paths with spaces embedded in them.
New split limit of 4 gets the required parts, because it
specifies the allowed number of splits, not elements:

mode type hash size name
    1    2    3    4

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

a name is deprecated.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

This is really useful when computing statistics over a set of
repositories, where some repositories are much older than other.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

This fixes a memory / ressource leak that manifests when computing
stats over big sets of repositories. It was eating more than 8G of
memory for ~15 git repositories.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Fix the base of graph y-axes at zero to prevent misleading graphics.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

The code already checks for python 2.6.

Without this, author names containing `touch /tmp/vulnerable` would cause said
file to appear after generating statistics for the given repository.

This is not an optimal solution. Instead of blacklisting characters we should
either whitelist some, or find a safe escape mechanism for gnuplot.

* author.txt was renamed to AUTHOR
* use git shortlog instead of git-shortlog
  because the latter is not necessarily in PATH

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

Default to 8.

Problem: gitstats will read every commit and every file in repository in one
thread during initial statistics generation (i.e. no cache available). It may
take much time in case of huge repositories (100 000+ files) Solution: Execute
all read commands in 24 threads instead of one

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>