Implemented a bunch of environment related NTDLL APIs.

diff --git a/include/winternl.h b/include/winternl.h
index 876ed13..77f92fb 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -951,7 +951,7 @@
 void      WINAPI RtlCopyString(STRING*,const STRING*);
 void      WINAPI RtlCopyUnicodeString(UNICODE_STRING*,const UNICODE_STRING*);
 NTSTATUS  WINAPI RtlCreateAcl(PACL,DWORD,DWORD);
-DWORD     WINAPI RtlCreateEnvironment(DWORD,DWORD);
+NTSTATUS  WINAPI RtlCreateEnvironment(BOOLEAN, PWSTR*);
 HANDLE    WINAPI RtlCreateHeap(ULONG,PVOID,ULONG,ULONG,PVOID,PRTL_HEAP_DEFINITION);
 NTSTATUS  WINAPI RtlCreateSecurityDescriptor(PSECURITY_DESCRIPTOR,DWORD);
 BOOLEAN   WINAPI RtlCreateUnicodeString(PUNICODE_STRING,LPCWSTR);
@@ -960,7 +960,7 @@
 NTSTATUS  WINAPI RtlDeleteCriticalSection(RTL_CRITICAL_SECTION *);
 void      WINAPI RtlDeleteResource(LPRTL_RWLOCK);
 DWORD     WINAPI RtlDeleteSecurityObject(DWORD);
-DWORD     WINAPI RtlDestroyEnvironment(DWORD);
+NTSTATUS  WINAPI RtlDestroyEnvironment(PWSTR);
 HANDLE    WINAPI RtlDestroyHeap(HANDLE);
 DOS_PATHNAME_TYPE WINAPI RtlDetermineDosPathNameType_U(PCWSTR);
 BOOLEAN   WINAPI RtlDosPathNameToNtPathName_U(LPWSTR,PUNICODE_STRING,DWORD,DWORD);
@@ -1076,7 +1076,7 @@
 BOOLEAN   WINAPI RtlPrefixString(const STRING*,const STRING*,BOOLEAN);
 BOOLEAN   WINAPI RtlPrefixUnicodeString(const UNICODE_STRING*,const UNICODE_STRING*,BOOLEAN);
 
-DWORD     WINAPI RtlQueryEnvironmentVariable_U(DWORD,PUNICODE_STRING,PUNICODE_STRING) ;
+NTSTATUS  WINAPI RtlQueryEnvironmentVariable_U(PWSTR,PUNICODE_STRING,PUNICODE_STRING);
 NTSTATUS  WINAPI RtlQueryTimeZoneInformation(LPTIME_ZONE_INFORMATION);
 
 void      WINAPI RtlRaiseException(PEXCEPTION_RECORD);
@@ -1090,8 +1090,9 @@
 void      WINAPI RtlSecondsSince1980ToTime(DWORD,LARGE_INTEGER *);
 void      WINAPI RtlSetAllBits(PRTL_BITMAP);
 void      WINAPI RtlSetBits(PRTL_BITMAP,ULONG,ULONG);
+void      WINAPI RtlSetCurrentEnvironment(PWSTR, PWSTR*);
 NTSTATUS  WINAPI RtlSetDaclSecurityDescriptor(PSECURITY_DESCRIPTOR,BOOLEAN,PACL,BOOLEAN);
-DWORD     WINAPI RtlSetEnvironmentVariable(DWORD,PUNICODE_STRING,PUNICODE_STRING);
+NTSTATUS  WINAPI RtlSetEnvironmentVariable(PWSTR*,PUNICODE_STRING,PUNICODE_STRING);
 NTSTATUS  WINAPI RtlSetOwnerSecurityDescriptor(PSECURITY_DESCRIPTOR,PSID,BOOLEAN);
 NTSTATUS  WINAPI RtlSetGroupSecurityDescriptor(PSECURITY_DESCRIPTOR,PSID,BOOLEAN);
 NTSTATUS  WINAPI RtlSetSaclSecurityDescriptor(PSECURITY_DESCRIPTOR,BOOLEAN,PACL,BOOLEAN);