Merge pull request #6 from msoucy/master

ACS and import fixes
Merge pull request #7 from msoucy/master

wattrset return value
nothrow
for function parameters: immutable -> const

immutable is too strong/restrictive
remove the wchar_t version of slk_set

C doesn't have overloading. curses.h defines the char one.
Merge pull request #11 from NilsBossung/slk_set

remove the wchar_t version of slk_set
Merge pull request #10 from NilsBossung/nothrow

nothrow
Merge pull request #9 from NilsBossung/const

for function parameters: immutable -> const
Merge pull request #8 from msoucy/master

Examples and documentation