change cover html generation to produce valid html

- added missing doctype
- added encoding statement
- removed invalid additional opening <body> tag
break overlong line
Avoid passing more than one instance of ERL_LIBS to child processes

This commit fixes issue #98 by removing the ERL_LIBS and REBAR_DEPS_DIR
from the list of environment variables exported by the rebar_port_compiler
plugin.
remove superfluous string concat operator usage
Allow the use of absolute paths in the lib_dirs configuration setting
When expanding lib_dirs, don't crash with 'volumerelative' paths
Merge pull request #101 from jcomellas/jc-absolute-lib-dirs

Allow the use of absolute paths in the lib_dirs configuration setting
Add one more "unicode" option in expand_env_variable—I have a bullet in my prompt that was blowing it up
Fix crash when env vars contain utf8 chars
Fix crsh with Unicode in environment vars
Merge pull request #102 from pragdave/master

Add one more "unicode" option in expand_env_variable—I have a bullet in my prompt that was blowing it up
Delete dialyzer_warnings on 'make distclean'
Update THANKS file
Remove vestiges of Mercurial repo
rebar_ct: fix Dialyzer warning caused by bcc57e9b

Also fix a single line exceeding max column.
rebar_core: fix consistency issues caused by 252b31f

- refactor plugin dirs code to be simpler and easier to read
- use erlang-mode's default (%%) comments for portability/consistency
- make sure erlang-mode's indenter is used so that a future whole
  buffer indent doesn't get messed up
rebar_xref: regression fixes and updates for a5be40c96

- restore support for "rebar help xref"
- update rebar.config.sample
- update 'help xref' string
- simplify new/changed functions by breaking out code or
  using simpler syntax where applicable
Merge pull request #99 from tuncer/fixes-and-updates

Fixes and updates
Merge pull request #41 from exterm/cover_html_validity

change cover html generation to produce valid html
Adding debug statements closer to open_port