Build problems with gpg 1.9.10 and cryptplugin 0.3.16

I've built and installed all GnuPG 1.9.10 related components (gpg, gpgme, 
ksban, gpg-error and libgcrypt) into /usr/local/lib. So far so good.

Now I try to build the CryptoPlugins because I want to use GnuPG as an S/MIME 
engine in KMail 1.6.2.

I use
./configure --enable-cryptplug-gpgme --with-gpgme-prefix=/usr/local

This yields:
        CryptPlug v0.3.16 has been configured as follows:
        CryptPlug GPGME: yes

In config.log I find:
"
GPGME_CFLAGS='-I/usr/local/include -I/usr/include'
GPGME_CONFIG='/usr/local/bin/gpgme-config'
GPGME_LIBS='-L/usr/local/lib -lgpgme -L/usr/lib -lgpg-error'
"

Unfortunately I get an error when I run make saying that 
"gpgmeplug.c:296: error: `GPGME_No_Error' undeclared (first use in this 
function)" plus a whole bunch of "deprecated" warnings.

I noticed that GPGME_No_Error is no longer defined in gpgme.h v.0.9.0 but it 
is defined in the old gpgme.h v.0.3.16.

The new .h files for GPG v19.10 et al are in my /usr/local/include whilst the 
old header files for GPG 1.3 are in /usr/include.

So, is CryptPlug still up to date? Is CryptPlug still needed to integrate 
GnuPG 1.9 in KMail? If not, how should I use GnuPG 1.9 with KMail?