README.txt: Fix path to README in Src/ dir

Change-Id: I1169ff765677d8f12b422b1beaa01cb0651d6d22
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>
README.txt: Point to Qt Creator 2.7 doc instead of 2.6

The latest installers ship Qt Creator 2.7 for opensource and
commercial/enterprise.

Change-Id: I2eda6a2d219d65cf46c12c37d7c3d39c117672a0
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>
README.txt: Fix strange list format

Change-Id: I29e890b0490dddd98d40177b08a498664ec0c557
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>