Add support for "!include: error in script:" error types
Merge pull request #3 from zenpoy/patch-1

Add support for "!include: error in script:" error types
added back qoute to language definition
Merge pull request #4 from zenpoy/patch-2

added back quote to language definition
Improve makensis.exe directory detection.

  - Add support for makensis.exe in PATH.
  - Add support for NSIS_HOME environment variable.
Merge pull request #6 from wernight/master

Support relative/portable NSIS
Updated readme: better installation, portablity
Merge remote-tracking branch 'upstream/master'