Extract html into its own file

HTML code is not embedded in python code anymore, but resides in its own
file, index.html
Interpolation of the version number and the IP address is made through
the '%s' syntax[0]. This requires that all other '%' chars are doubled,
which happens 3 times in URLs with '%20' for spaces.

0: the 'format' syntax should be preferred, however it requires that all
'{' and '}' are doubled, which is more work because CSS.
Config file write: use context manager

The use of a context manager to open 'config.ini' ensures proper closing
& handling of problems in any case.
conf.ini location does not depend on launch dir

`conf.ini` search location used to depend on the work directory.
Therefore if the application were once launched from home and then from
`foo` folder, 2 `conf.ini` would be written: `~/conf.ini` and
`~/foo/conf.ini`, which is a problem:
- causes pollution
- in case of a custom configuration, if would not be used

The config file is now searched side by side with the py file.
Icon path: avoid using `inspect` module

The icon file path is retrieved using __file__[0] instead of
inspect.getcurrentframe().
This is faster and cleaner than using inspection of the stack.

0: through the variable `current_dir` used for config & html
   template file as well
Config. instruction message: avoid code repetition

Write the message once in a variable instead of writing it twice,
because code redundancy is baad.
Added gitignore, removed eclipse files
Follow PEP8 style guide

For cleaner and more comprehensible code, apply PEP8[0] instructions :
- No trailing whitespace
- Correct number of empty lines
- Some other spaces-related stuff
- Correct import ordering

0: http://www.python.org/dev/peps/pep-0008/
Merge pull request #5 from brunal/master

Code robustness: better paths, templating, unique conf. location, PEP8