[CMake] List in some cases ignores empty list items if they are at the beginning of the list

[Svami Dhyan Nataraj]

List in some cases ignores empty list items if they are at the begining
of the list. Here is an example:

cmake_policy(SET CMP0007 NEW) # do not ignore empty list item in list
command SET(text "1;;2;;;;3;4;")
WHILE(${text})
  list(GET text 0 str)
  list(REMOVE_AT text 0)
  MESSAGE(STATUS "-${str}-").
ENDWHILE(${ui_text})

running it we will get 
-- -1-
-- -2-
-- -3-

empty lines are skipped

but if we add dummy non-empty at the beginning of the list, and then
remove second elements one by one, everything would work as expected:

cmake_policy(SET CMP0007 NEW) # do not ignore empty list item in list
command SET(text "1;;2;;;;3;4;")
SET(text "dummy_line;${text}")

WHILE(NOT text STREQUAL "dummy_line" )
  list(GET text 1 str)
  list(REMOVE_AT text 1)
  MESSAGE(STATUS "-${str}-").
ENDWHILE(NOT text STREQUAL "dummy_line" )

we will get:

-- -1-
-- --
-- -2-
-- --
-- --
-- --
-- -3-
-- -4-
-- --

$ cmake --version
cmake version 2.6-patch 0

I think that is not nice behavior. If you consider it bug, I can
officially report it to the bug tracker.

PS, there is also problem with FOREACH with list with empty lines... I
do not know wether it should be so or not...